mtd: Fix possible refcounting issue when going through partition nodes

Under normal conditions, the loop goes over all child partitions, and
'breaks' when the relevant partition is found. In this case we get a
reference to the partition node without ever releasing it. Indeed, right
after the mtd_check_of_node() function returns, we call of_node_get()
again over this very same node. It is probably safer to keep the
counters even in this helper and call of_node_put() before break-ing.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Julia Lawall <julia.lawall@inria.fr>
Closes: https://lore.kernel.org/r/202312250546.ISzglvM2-lkp@intel.com/
Cc: Christian Marangi <ansuelsmth@gmail.com>
Cc: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20240104081446.126540-1-miquel.raynal@bootlin.com

mtd: Add several functions to the fail_function list

add mtd_read(), mtd_write(), mtd_erase(), mtd_block_markbad() to
fail_function list for testing purpose

- Specify the function to inject the fault
echo mtd_read > /sys/kernel/debug/fail_function/inject

- Specifies the return value of the function to inject the fault
printf %#x -12 > /sys/kernel/debug/fail_function/mtd_read/retval

- Specify other fault injection configuration parameters.
echo -1 > /sys/kernel/debug/fail_function/times
echo 100 > /sys/kernel/debug/fail_function/probability
echo 15 > /sys/kernel/debug/fail_function/space

Signed-off-by: ZhaoLong Wang <wangzhaolong1@huawei.com>
Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

Revert "nvmem: add new config option"

This reverts commit 517f14d9cf3533d5ab4fded195ab6f80a92e378f.

Config option "no_of_node" is no longer needed since adding a more
explicit and targeted option "add_legacy_fixed_of_cells".

That "no_of_node" config option was needed *earlier* to help mtd's case.

DT nodes of MTD partitions (that are also NVMEM devices) may contain
subnodes. Those SHOULD NOT be treated as NVMEM fixed cells.

To prevent NVMEM core code from parsing subnodes a "no_of_node" option
was added (and set to true in mtd) to make for_each_child_of_node() in
NVMEM a no-op. That was a bit hacky because it was messing with
"of_node" pointer to achieve some side-effect.

With the introduction of "add_legacy_fixed_of_cells" config option
things got more explicit. MTD subsystem simply tells NVMEM when to look
for fixed cells and there is no need to hack "of_node" pointer anymore.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231023102759.31529-1-zajec5@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

nvmem: add explicit config option to read old syntax fixed OF cells

Binding for fixed NVMEM cells defined directly as NVMEM device subnodes
has been deprecated. It has been replaced by the "fixed-layout" NVMEM
layout binding.

New syntax is meant to be clearer and should help avoiding imprecise
bindings.

NVMEM subsystem already supports the new binding. It should be a good
idea to limit support for old syntax to existing drivers that actually
support & use it (we can't break backward compatibility!). That way we
additionally encourage new bindings & drivers to ignore deprecated
binding.

It wasn't clear (to me) if rtc and w1 code actually uses old syntax
fixed cells. I enabled them to don't risk any breakage.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
[for meson-{efuse,mx-efuse}.c]
Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
[for mtk-efuse.c, nvmem/core.c, nvmem-provider.h]
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
[MT8192, MT8195 Chromebooks]
Tested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
[for microchip-otpc.c]
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
[SAMA7G5-EK]
Tested-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231020105545.216052-3-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mtd: Add WARN_ON_ONCE() to mtd_read() to check the return value

If the driver cannot read all the requested data, -EBADMSG or
-EUCLEAN should never be returned.

Add a WARN_ON_ONCE() to help driver developers detect this error.

Signed-off-by: ZhaoLong Wang <wangzhaolong1@huawei.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230926065733.3240322-1-wangzhaolong1@huawei.com

mtd: Clean refcounting with MTD_PARTITIONED_MASTER

The logic is way too convoluted, let's clean the kref_get/put section to
clarify what this block does when using CONFIG_MTD_PARTITIONED_MASTER:
- Iterate through all the parent mtd devices
- Grab a reference over them all but the master
- Only grab the master whith CONFIG_MTD_PARTITIONED_MASTER
Same logic must apply in the put path, otherwise it would be broken.

Cc: Tomas Winkler <tomas.winkler@intel.com>
Cc: Alexander Usyskin <alexander.usyskin@intel.com>
Cc: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Fixes: 19bfa9ebebb5 ("mtd: use refcount to prevent corruption")
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Tested-by: Alexander Usyskin <alexander.usyskin@intel.com>
Link: https://lore.kernel.org/linux-mtd/20230731090903.770277-1-miquel.raynal@bootlin.com

mtd: fix use-after-free in mtd release

I case of partition device_unregister() in mtd_device_release()
calls mtd_release() which frees mtd_info structure for partition.
All code after device_unregister in mtd_device_release thus
uses already freed memory.

Move part of code to mtd_release() and restict mtd->dev cleanup
to non-partion object.
For partition object such cleanup have no sense as partition
mtd_info is removed.

Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Fixes: 19bfa9ebebb5 ("mtd: use refcount to prevent corruption")
Reviewed-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230731115836.542747-1-alexander.usyskin@intel.com

mtd: call external _get and _put in right order

MTD provider provides mtd_info object to mtd subsystem.
With kref patch the mtd_info object can be alive after
provider released mtd device.
Fix calling order in _get and _put functions to allow
mtd provider to safely alloc and release mtd object.

Execute:
1) call external _get
2) get_module
3) add internal kref
in the get function and opposite order in the put one.

The _put_device callback should be the last in put
as the master struct memory may be freed in this callback.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230620131905.648089-3-alexander.usyskin@intel.com

mtd: use refcount to prevent corruption

When underlying device is removed mtd core will crash
in case user space is holding open handle.
Need to use proper refcounting so device is release
only when has no users.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230620131905.648089-2-alexander.usyskin@intel.com

mtd: otp: clean up on error in mtd_otp_nvmem_add()

Smatch complains that these error paths are missing cleanup:

drivers/mtd/mtdcore.c:983 mtd_otp_nvmem_add()
warn: missing unwind goto?

This needs to call nvmem_unregister(mtd->otp_user_nvmem) before
returning.

Fixes: 3b270fac8443 ("mtd: otp: Put factory OTP/NVRAM into the entropy pool")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/fe7ef901-9571-4c6e-a40e-449046efe2c6@moroto.mountain

mtd: otp: Put factory OTP/NVRAM into the entropy pool

The factory OTP, if supported, contains factory-programmed
information such as typically the serial number or production
week for the chip.

As this is device-unique information, submit it into the
system entropy pool.

This does not count as improvement of the entropy as such
but in practice it makes it a bit more random to mix in these
numbers.

Cc: Michael Walle <michael@walle.cc>
Acked-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230606142931.3721374-1-linus.walleij@linaro.org

drivers: remove struct module * setting from struct class

There is no need to manually set the owner of a struct class, as the
registering function does it automatically, so remove all of the
explicit settings from various drivers that did so as it is unneeded.

This allows us to remove this pointer entirely from this structure going
forward.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230313181843.1207845-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mtd: Use of_property_read_bool() for boolean properties

It is preferred to use typed property access functions (i.e.
of_property_read_<type> functions) rather than low-level
of_get_property/of_find_property functions for reading properties.
Convert reading boolean properties to to of_property_read_bool().

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230310144716.1543995-1-robh@kernel.org

mtd: Avoid magic values

Nvmem producer config ID "-1" is actually defined, so use the definition
rather than hardcoding it with a magic value.

Suggested-by: Michael Walle <michael@walle.cc>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/linux-mtd/20230307192536.470997-1-miquel.raynal@bootlin.com

mtd: Avoid printing error messages on probe deferrals

There is no reason to complain about probe errors in case of deferrals.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/linux-mtd/20230307192506.439532-1-miquel.raynal@bootlin.com

mtd: core: prepare mtd_otp_nvmem_add() to handle -EPROBE_DEFER

NVMEM soon will get the ability for nvmem layouts and these might
not be ready when nvmem_register() is called and thus it might
return -EPROBE_DEFER. Don't print the error message in this case.

Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230308082021.870459-4-michael@walle.cc

mtd: core: fix error path for nvmem provider

If mtd_otp_nvmem_add() fails, the partitions won't be removed
because there is simply no call to del_mtd_partitions().
Unfortunately, add_mtd_partitions() will print all partitions to
the kernel console. If mtd_otp_nvmem_add() returns -EPROBE_DEFER
this would print the partitions multiple times to the kernel
console. Instead move mtd_otp_nvmem_add() to the beginning of the
function.

Fixes: 4b361cfa8624 ("mtd: core: add OTP nvmem provider support")
Cc: stable@vger.kernel.org
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230308082021.870459-3-michael@walle.cc

mtd: core: fix nvmem error reporting

The master MTD will only have an associated device if
CONFIG_MTD_PARTITIONED_MASTER is set, thus we cannot use dev_err() on
mtd->dev. Instead use the parent device which is the physical flash
memory.

Fixes: 4b361cfa8624 ("mtd: core: add OTP nvmem provider support")
Cc: stable@vger.kernel.org
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230308082021.870459-2-michael@walle.cc

mtd: core: provide unique name for nvmem device, take two

Commit c048b60d39e1 ("mtd: core: provide unique name for nvmem device")
tries to give the nvmem device a unique name, but fails badly if the mtd
device doesn't have a "struct device" associated with it, i.e. if
CONFIG_MTD_PARTITIONED_MASTER is not set. This will result in the name
"(null)-user-otp", which is not unique. It seems the best we can do is
to use the compatible name together with a unique identifier added by
the nvmem subsystem by using NVMEM_DEVID_AUTO.

Fixes: c048b60d39e1 ("mtd: core: provide unique name for nvmem device")
Cc: stable@vger.kernel.org
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230308082021.870459-1-michael@walle.cc

mtd: core: Fix refcount error in del_mtd_device()

del_mtd_device() will call of_node_put() to mtd_get_of_node(mtd), which
is mtd->dev.of_node. However, memset(&mtd->dev, 0) is called before
of_node_put(). As the result, of_node_put() won't do anything in
del_mtd_device(), and causes the refcount leak.

del_mtd_device()
memset(&mtd->dev, 0, sizeof(mtd->dev) # clear mtd->dev
of_node_put()
mtd_get_of_node(mtd) # mtd->dev is cleared, can't locate of_node
# of_node_put(NULL) won't do anything

Fix the error by caching the pointer of the device_node.

OF: ERROR: memory leak, expected refcount 1 instead of 2,
of_node_get()/of_node_put() unbalanced - destroy cset entry: attach
overlay node /spi/spi-sram@0
CPU: 3 PID: 275 Comm: python3 Tainted: G N 6.1.0-rc3+ #54
0d8a1edddf51f172ff5226989a7565c6313b08e2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x67/0x83
kobject_get+0x155/0x160
of_node_get+0x1f/0x30
of_fwnode_get+0x43/0x70
fwnode_handle_get+0x54/0x80
fwnode_get_nth_parent+0xc9/0xe0
fwnode_full_name_string+0x3f/0xa0
device_node_string+0x30f/0x750
pointer+0x598/0x7a0
vsnprintf+0x62d/0x9b0
...
cfs_overlay_release+0x30/0x90
config_item_release+0xbe/0x1a0
config_item_put+0x5e/0x80
configfs_rmdir+0x3bd/0x540
vfs_rmdir+0x18c/0x320
do_rmdir+0x198/0x330
__x64_sys_rmdir+0x2c/0x40
do_syscall_64+0x37/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fixes: 00596576a051 ("mtd: core: clear out unregistered devices a bit more")
Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
[<miquel.raynal@bootlin.com>: Light reword of the commit log]
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20221119063915.11108-1-shangxiaojing@huawei.com

mtd: core: fix possible resource leak in init_mtd()

I got the error report while inject fault in init_mtd():

sysfs: cannot create duplicate filename '/devices/virtual/bdi/mtd-0'
Call Trace:
<TASK>
dump_stack_lvl+0x67/0x83
sysfs_warn_dup+0x60/0x70
sysfs_create_dir_ns+0x109/0x120
kobject_add_internal+0xce/0x2f0
kobject_add+0x98/0x110
device_add+0x179/0xc00
device_create_groups_vargs+0xf4/0x100
device_create+0x7b/0xb0
bdi_register_va.part.13+0x58/0x2d0
bdi_register+0x9b/0xb0
init_mtd+0x62/0x171 [mtd]
do_one_initcall+0x6c/0x3c0
do_init_module+0x58/0x222
load_module+0x268e/0x27d0
__do_sys_finit_module+0xd5/0x140
do_syscall_64+0x37/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
</TASK>
kobject_add_internal failed for mtd-0 with -EEXIST, don't try to register
things with the same name in the same directory.
Error registering mtd class or bdi: -17

If init_mtdchar() fails in init_mtd(), mtd_bdi will not be unregistered,
as a result, we can't load the mtd module again, to fix this by calling
bdi_unregister(mtd_bdi) after out_procfs label.

Fixes: 445caaa20c4d ("mtd: Allocate bdi objects dynamically")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20221024065109.2050705-1-cuigaosheng1@huawei.com

mtd: core: set ROOT_DEV for partitions marked as rootfs in DT

This adds support for "linux,rootfs" binding that is used to mark flash
partition containing rootfs. It's useful for devices using device tree
that don't have bootloader passing root info in cmdline.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20221022211318.32009-2-zajec5@gmail.com

mtd: Fix device name leak when register device failed in add_mtd_device()

There is a kmemleak when register device failed:
unreferenced object 0xffff888101aab550 (size 8):
comm "insmod", pid 3922, jiffies 4295277753 (age 925.408s)
hex dump (first 8 bytes):
6d 74 64 30 00 88 ff ff mtd0....
backtrace:
[<00000000bde26724>] __kmalloc_node_track_caller+0x4e/0x150
[<000000003c32b416>] kvasprintf+0xb0/0x130
[<000000001f7a8f15>] kobject_set_name_vargs+0x2f/0xb0
[<000000006e781163>] dev_set_name+0xab/0xe0
[<00000000e30d0c78>] add_mtd_device+0x4bb/0x700
[<00000000f3d34de7>] mtd_device_parse_register+0x2ac/0x3f0
[<00000000c0d88488>] 0xffffffffa0238457
[<00000000b40d0922>] 0xffffffffa02a008f
[<0000000023d17b9d>] do_one_initcall+0x87/0x2a0
[<00000000770f6ca6>] do_init_module+0xdf/0x320
[<000000007b6768fe>] load_module+0x2f98/0x3330
[<00000000346bed5a>] __do_sys_finit_module+0x113/0x1b0
[<00000000674c2290>] do_syscall_64+0x35/0x80
[<000000004c6a8d97>] entry_SYSCALL_64_after_hwframe+0x46/0xb0

If register device failed, should call put_device() to give up the
reference.

Fixes: 1f24b5a8ecbb ("[MTD] driver model updates")
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20221022121352.2534682-1-zhangxiaoxu5@huawei.com

mtd: core: try to find OF node for every MTD partition

So far this feature was limited to the top-level "nvmem-cells" node.
There are multiple parsers creating partitions and subpartitions
dynamically. Extend that code to handle them too.

This allows finding partition-* node for every MTD (sub)partition.

Random example:

partitions {
compatible = "brcm,bcm947xx-cfe-partitions";

partition-firmware {
compatible = "brcm,trx";

partition-loader {
};
};
};

Cc: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20221004083710.27704-2-zajec5@gmail.com

mtd: core: simplify (a bit) code find partition-matching dynamic OF node

1. Don't hardcode "partition-" string twice
2. Use simpler logic & use ->name to avoid of_property_read_string()
3. Use mtd_get_of_node() helper

Cc: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20221004083710.27704-1-zajec5@gmail.com

mtd: core: add missing of_node_get() in dynamic partitions code

This fixes unbalanced of_node_put():
[ 1.078910] 6 cmdlinepart partitions found on MTD device gpmi-nand
[ 1.085116] Creating 6 MTD partitions on "gpmi-nand":
[ 1.090181] 0x000000000000-0x000008000000 : "nandboot"
[ 1.096952] 0x000008000000-0x000009000000 : "nandfit"
[ 1.103547] 0x000009000000-0x00000b000000 : "nandkernel"
[ 1.110317] 0x00000b000000-0x00000c000000 : "nanddtb"
[ 1.115525] ------------[ cut here ]------------
[ 1.120141] refcount_t: addition on 0; use-after-free.
[ 1.125328] WARNING: CPU: 0 PID: 1 at lib/refcount.c:25 refcount_warn_saturate+0xdc/0x148
[ 1.133528] Modules linked in:
[ 1.136589] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.0.0-rc7-next-20220930-04543-g8cf3f7
[ 1.146342] Hardware name: Freescale i.MX8DXL DDR3L EVK (DT)
[ 1.151999] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 1.158965] pc : refcount_warn_saturate+0xdc/0x148
[ 1.163760] lr : refcount_warn_saturate+0xdc/0x148
[ 1.168556] sp : ffff800009ddb080
[ 1.171866] x29: ffff800009ddb080 x28: ffff800009ddb35a x27: 0000000000000002
[ 1.179015] x26: ffff8000098b06ad x25: ffffffffffffffff x24: ffff0a00ffffff05
[ 1.186165] x23: ffff00001fdf6470 x22: ffff800009ddb367 x21: 0000000000000000
[ 1.193314] x20: ffff00001fdfebe8 x19: ffff00001fdfec50 x18: ffffffffffffffff
[ 1.200464] x17: 0000000000000000 x16: 0000000000000118 x15: 0000000000000004
[ 1.207614] x14: 0000000000000fff x13: ffff800009bca248 x12: 0000000000000003
[ 1.214764] x11: 00000000ffffefff x10: c0000000ffffefff x9 : 4762cb2ccb52de00
[ 1.221914] x8 : 4762cb2ccb52de00 x7 : 205d313431303231 x6 : 312e31202020205b
[ 1.229063] x5 : ffff800009d55c1f x4 : 0000000000000001 x3 : 0000000000000000
[ 1.236213] x2 : 0000000000000000 x1 : ffff800009954be6 x0 : 000000000000002a
[ 1.243365] Call trace:
[ 1.245806] refcount_warn_saturate+0xdc/0x148
[ 1.250253] kobject_get+0x98/0x9c
[ 1.253658] of_node_get+0x20/0x34
[ 1.257072] of_fwnode_get+0x3c/0x54
[ 1.260652] fwnode_get_nth_parent+0xd8/0xf4
[ 1.264926] fwnode_full_name_string+0x3c/0xb4
[ 1.269373] device_node_string+0x498/0x5b4
[ 1.273561] pointer+0x41c/0x5d0
[ 1.276793] vsnprintf+0x4d8/0x694
[ 1.280198] vprintk_store+0x164/0x528
[ 1.283951] vprintk_emit+0x98/0x164
[ 1.287530] vprintk_default+0x44/0x6c
[ 1.291284] vprintk+0xf0/0x134
[ 1.294428] _printk+0x54/0x7c
[ 1.297486] of_node_release+0xe8/0x128
[ 1.301326] kobject_put+0x98/0xfc
[ 1.304732] of_node_put+0x1c/0x28
[ 1.308137] add_mtd_device+0x484/0x6d4
[ 1.311977] add_mtd_partitions+0xf0/0x1d0
[ 1.316078] parse_mtd_partitions+0x45c/0x518
[ 1.320439] mtd_device_parse_register+0xb0/0x274
[ 1.325147] gpmi_nand_probe+0x51c/0x650
[ 1.329074] platform_probe+0xa8/0xd0
[ 1.332740] really_probe+0x130/0x334
[ 1.336406] __driver_probe_device+0xb4/0xe0
[ 1.340681] driver_probe_device+0x3c/0x1f8
[ 1.344869] __driver_attach+0xdc/0x1a4
[ 1.348708] bus_for_each_dev+0x80/0xcc
[ 1.352548] driver_attach+0x24/0x30
[ 1.356127] bus_add_driver+0x108/0x1f4
[ 1.359967] driver_register+0x78/0x114
[ 1.363807] __platform_driver_register+0x24/0x30
[ 1.368515] gpmi_nand_driver_init+0x1c/0x28
[ 1.372798] do_one_initcall+0xbc/0x238
[ 1.376638] do_initcall_level+0x94/0xb4
[ 1.380565] do_initcalls+0x54/0x94
[ 1.384058] do_basic_setup+0x1c/0x28
[ 1.387724] kernel_init_freeable+0x110/0x188
[ 1.392084] kernel_init+0x20/0x1a0
[ 1.395578] ret_from_fork+0x10/0x20
[ 1.399157] ---[ end trace 0000000000000000 ]---
[ 1.403782] ------------[ cut here ]------------

Reported-by: Han Xu <han.xu@nxp.com>
Fixes: ad9b10d1eaada169 ("mtd: core: introduce of support for dynamic partitions")
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Tested-by: Han Xu <han.xu@nxp.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20221018051822.28685-1-zajec5@gmail.com

mtd: allow getting MTD device associated with a specific DT node

MTD subsystem API allows interacting with MTD devices (e.g. reading,
writing, handling bad blocks). So far a random driver could get MTD
device only by its name (get_mtd_device_nm()). This change allows
getting them also by a DT node.

This API is required for drivers handling DT defined MTD partitions in a
specific way (e.g. U-Boot (sub)partition with environment variables).

Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20220916122100.170016-3-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mtd: track maximum number of bitflips for each read request

mtd_read_oob() callers are currently oblivious to the details of ECC
errors detected during the read operation - they only learn (through the
return value) whether any corrected bitflips or uncorrectable errors
occurred. More detailed ECC information can be useful to user-space
applications for making better-informed choices about moving data
around.

Extend struct mtd_oob_ops with a pointer to a newly-introduced struct
mtd_req_stats and set its 'max_bitflips' field to the maximum number of
bitflips found in a single ECC step during the read operation performed
by mtd_read_oob(). This is a prerequisite for ultimately passing that
value back to user space.

Suggested-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220629125737.14418-2-kernel@kempniu.pl

mtd: core: check partition before dereference

syzbot is reporting NULL pointer dereference at mtd_check_of_node() [1],
for mtdram test device (CONFIG_MTD_MTDRAM) is not partition.

Link: https://syzkaller.appspot.com/bug?extid=fe013f55a2814a9e8cfd [1]
Reported-by: syzbot <syzbot+fe013f55a2814a9e8cfd@syzkaller.appspotmail.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Fixes: ad9b10d1eaada169 ("mtd: core: introduce of support for dynamic partitions")
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
CC: stable@vger.kernel.org
Signed-off-by: Richard Weinberger <richard@nod.at>

mtd: core: introduce of support for dynamic partitions

We have many parser that register mtd partitions at runtime. One example
is the cmdlinepart or the smem-part parser where the compatible is defined
in the dts and the partitions gets detected and registered by the
parser. This is problematic for the NVMEM subsystem that requires an OF
node to detect NVMEM cells.

To fix this problem, introduce an additional logic that will try to
assign an OF node to the MTD if declared.

On MTD addition, it will be checked if the MTD has an OF node and if
not declared will check if a partition with the same label / node name is
declared in DTS. If an exact match is found, the partition dynamically
allocated by the parser will have a connected OF node.

The NVMEM subsystem will detect the OF node and register any NVMEM cells
declared statically in the DTS.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220622010628.30414-4-ansuelsmth@gmail.com

mtd: core: Check devicetree alias for index

Allow the MTD index to be specified via a devicetree alias, so that the
number does not just depend on probe order. This is useful to allow
pseudo-devices like phram to be optionally used on systems, without
having this affect the numbering of the real hardware MTD devices.

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220412135302.1682890-2-vincent.whitchurch@axis.com

mtd: core: Drop duplicate NULL checks around nvmem_unregister()

Since nvmem_unregister() checks for NULL, no need to repeat in
the caller. Drop duplicate NULL checks.

Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20220220151527.17216-13-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mtd: core: Remove partid and partname debugfs files

partid and partname debugfs files were used just by SPI NOR, but they were
replaced by sysfs entries. Since these debugfs files are no longer used in
mtd, remove dead code. The directory is kept as it is used by nandsim,
mtdswap and docg3.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Pratyush Yadav <p.yadav@ti.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220225144656.634682-1-tudor.ambarus@microchip.com

mtd: Replace the expert mode symbols with a single helper

Reduce the number of exported symbols by replacing:
- mtd_expert_analysis_warning (the error string)
- mtd_expert_analysis_mode (the boolean)
with a single helper:
- mtd_check_expert_analysis_mode

Calling this helper will both check/return the content of the internal
boolean -which is not exported anymore- and as well conditionally
WARN_ONCE() the user, like it was done before.

While on this function, make the error string local to the helper and
set it const. Only export this helper when CONFIG_DEBUG_FS is defined to
limit the growth of the Linux kernel size only for a debug feature on
production kernels.

Mechanically update all the consumers.

Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220128113414.1121924-1-miquel.raynal@bootlin.com

mtd: core: Fix a conflict between MTD and NVMEM on wp-gpios property

Wp-gpios property can be used on NVMEM nodes and the same property can
be also used on MTD NAND nodes. In case of the wp-gpios property is
defined at NAND level node, the GPIO management is done at NAND driver
level. Write protect is disabled when the driver is probed or resumed
and is enabled when the driver is released or suspended.

When no partitions are defined in the NAND DT node, then the NAND DT node
will be passed to NVMEM framework. If wp-gpios property is defined in
this node, the GPIO resource is taken twice and the NAND controller
driver fails to probe.

A new Boolean flag named ignore_wp has been added in nvmem_config.
In case ignore_wp is set, it means that the GPIO is handled by the
provider. Lets set this flag in MTD layer to avoid the conflict on
wp_gpios property.

Fixes: 2a127da461a9 ("nvmem: add support for the write-protect pin")
Cc: stable@vger.kernel.org
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Christophe Kerello <christophe.kerello@foss.st.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20220220151432.16605-3-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mtd: Introduce an expert mode for forensics and debugging purposes

When developping NAND controller drivers or when debugging filesystem
corruptions, it is quite common to need hacking locally into the
MTD/NAND core in order to get access to the content of the bad
blocks. Instead of having multiple implementations out there let's
provide a simple yet effective specific MTD-wide debugfs entry to fully
disable these checks on purpose.

A warning is added to inform the user when this mode gets enabled.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20211118114659.1282855-1-miquel.raynal@bootlin.com

mtd: core: clear out unregistered devices a bit more

This allows an MTD device that has been unregistered to be easily
re-registered later without triggering spurious "already registered"
warnings in mtd_device_parse_register() and add_mtd_device().

Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20211015185049.3318-1-zev@bewilderbeest.net

mtd: core: provide unique name for nvmem device

If there is more than one mtd device which supports OTP, there will
be a kernel warning about duplicated sysfs entries and the probing will
fail. This is because the nvmem device name is not unique. Make it
unique by prepending the name of the mtd. E.g. before the name was
"user-otp", now it will be "mtd0-user-otp".

For reference the kernel splash is:
[ 4.665531] sysfs: cannot create duplicate filename '/bus/nvmem/devices/user-otp'
[ 4.673056] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.15.0-next-20211101+ #1296
[ 4.680565] Hardware name: Kontron SMARC-sAL28 (Single PHY) on SMARC Eval 2.0 carrier (DT)
[ 4.688856] Call trace:
[ 4.691303] dump_backtrace+0x0/0x1bc
[ 4.694984] show_stack+0x24/0x30
[ 4.698306] dump_stack_lvl+0x68/0x84
[ 4.701980] dump_stack+0x18/0x34
[ 4.705302] sysfs_warn_dup+0x70/0x90
[ 4.708973] sysfs_do_create_link_sd+0x144/0x150
[ 4.713603] sysfs_create_link+0x2c/0x50
[ 4.717535] bus_add_device+0x74/0x120
[ 4.721293] device_add+0x330/0x890
[ 4.724791] device_register+0x2c/0x40
[ 4.728550] nvmem_register+0x240/0x9f0
[ 4.732398] mtd_otp_nvmem_register+0xb0/0x10c
[ 4.736854] mtd_device_parse_register+0x28c/0x2b4
[ 4.741659] spi_nor_probe+0x20c/0x2e0
[ 4.745418] spi_mem_probe+0x78/0xbc
[ 4.749001] spi_probe+0x90/0xf0
[ 4.752237] really_probe.part.0+0xa4/0x320
..
[ 4.873936] mtd mtd1: Failed to register OTP NVMEM device
[ 4.894468] spi-nor: probe of spi0.0 failed with error -17

Fixes: 4b361cfa8624 ("mtd: core: add OTP nvmem provider support")
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20211104134843.2642800-1-michael@walle.cc

mtd: core: don't remove debugfs directory if device is in use

Previously, if del_mtd_device() failed with -EBUSY due to a non-zero
usecount, a subsequent call to attempt the deletion again would try to
remove a debugfs directory that had already been removed and panic.
With this change the second call can instead proceed safely.

Fixes: e8e3edb95ce6 ("mtd: create per-device and module-scope debugfs entries")
Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20211014203953.5424-1-zev@bewilderbeest.net

mtd: call bdi_unregister explicitly

Call bdi_unregister explicitly instead of relying on the automatic
unregistration.

Link: https://lkml.kernel.org/r/20211021124441.668816-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mtd: core: handle flashes without OTP gracefully

There are flash drivers which registers the OTP callbacks although the
flash doesn't support OTP regions and return -ENODATA for these
callbacks if there is no OTP. If this happens, the probe of the whole
flash will fail. Fix it by handling the ENODATA return code and skip
the OTP region nvmem setup.

Fixes: 4b361cfa8624 ("mtd: core: add OTP nvmem provider support")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Michael Walle <michael@walle.cc>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210707135359.32398-1-michael@walle.cc

mtd: core: use MTD_DEVICE_ATTR_RO/RW() helper macros

Use MTD_DEVICE_ATTR_RO/RW() helper macros instead of plain DEVICE_ATTR(),
which makes the code a bit shorter and easier to read.

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210603125323.12142-3-thunder.leizhen@huawei.com

mtd: core: add MTD_DEVICE_ATTR_RO/RW() helper macros

Compared with the definition of DEVICE_ATTR_RO/RW(), the read and write
function names of the sysfs attribute have an additional "mtd_" prefix.

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210603125323.12142-2-thunder.leizhen@huawei.com

mtd: core: Potential NULL dereference in mtd_otp_size()

If kmalloc() fails then it could lead to a NULL dereference. Check and
return -ENOMEM on error.

Fixes: 4b361cfa8624 ("mtd: core: add OTP nvmem provider support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Michael Walle <michael@walle.cc>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/YJ6Iw3iNvGycAWV6@mwanda

mtd: core: Fix freeing of otp_info buffer

Commit 4b361cfa8624 ("mtd: core: add OTP nvmem provider support") is
causing the following panic ...

------------[ cut here ]------------
kernel BUG at /local/workdir/tegra/linux_next/kernel/mm/slab.c:2730!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 3 PID: 1 Comm: swapper/0 Not tainted 5.13.0-rc2-next-20210518 #1
Hardware name: NVIDIA Tegra SoC (Flattened Device Tree)
PC is at ___cache_free+0x3f8/0x51c
...
[<c029bb1c>] (___cache_free) from [<c029c658>] (kfree+0xac/0x1bc)
[<c029c658>] (kfree) from [<c06da094>] (mtd_otp_size+0xc4/0x108)
[<c06da094>] (mtd_otp_size) from [<c06dc864>] (mtd_device_parse_register+0xe4/0x2b4)
[<c06dc864>] (mtd_device_parse_register) from [<c06e3ccc>] (spi_nor_probe+0x210/0x2c0)
[<c06e3ccc>] (spi_nor_probe) from [<c06e9578>] (spi_probe+0x88/0xac)
[<c06e9578>] (spi_probe) from [<c066891c>] (really_probe+0x214/0x3a4)
[<c066891c>] (really_probe) from [<c0668b14>] (driver_probe_device+0x68/0xc0)
[<c0668b14>] (driver_probe_device) from [<c0666cf8>] (bus_for_each_drv+0x5c/0xbc)
[<c0666cf8>] (bus_for_each_drv) from [<c0668694>] (__device_attach+0xe4/0x150)
[<c0668694>] (__device_attach) from [<c06679e0>] (bus_probe_device+0x84/0x8c)
[<c06679e0>] (bus_probe_device) from [<c06657f8>] (device_add+0x48c/0x868)
[<c06657f8>] (device_add) from [<c06eb784>] (spi_add_device+0xa0/0x168)
[<c06eb784>] (spi_add_device) from [<c06ec9a8>] (spi_register_controller+0x8b8/0xb38)
[<c06ec9a8>] (spi_register_controller) from [<c06ecc3c>] (devm_spi_register_controller+0x14/0x50)
[<c06ecc3c>] (devm_spi_register_controller) from [<c06f0510>] (tegra_spi_probe+0x33c/0x450)
[<c06f0510>] (tegra_spi_probe) from [<c066abec>] (platform_probe+0x5c/0xb8)
[<c066abec>] (platform_probe) from [<c066891c>] (really_probe+0x214/0x3a4)
[<c066891c>] (really_probe) from [<c0668b14>] (driver_probe_device+0x68/0xc0)
[<c0668b14>] (driver_probe_device) from [<c0668e30>] (device_driver_attach+0x58/0x60)
[<c0668e30>] (device_driver_attach) from [<c0668eb8>] (__driver_attach+0x80/0xc8)
[<c0668eb8>] (__driver_attach) from [<c0666c48>] (bus_for_each_dev+0x78/0xb8)
[<c0666c48>] (bus_for_each_dev) from [<c0667c44>] (bus_add_driver+0x164/0x1e8)
[<c0667c44>] (bus_add_driver) from [<c066997c>] (driver_register+0x7c/0x114)
[<c066997c>] (driver_register) from [<c010223c>] (do_one_initcall+0x50/0x2b0)
[<c010223c>] (do_one_initcall) from [<c11011f0>] (kernel_init_freeable+0x1a8/0x1fc)
[<c11011f0>] (kernel_init_freeable) from [<c0c09190>] (kernel_init+0x8/0x118)
[<c0c09190>] (kernel_init) from [<c01001b0>] (ret_from_fork+0x14/0x24)
...
---[ end trace 0f652dd222de75d7 ]---

In the function mtd_otp_size() a buffer is allocated by calling
kmalloc() and a pointer to the buffer is stored in a variable 'info'.
The pointer 'info' may then be incremented depending on the length
returned from mtd_get_user/fact_prot_info(). If 'info' is incremented,
when kfree() is called to free the buffer the above panic occurs because
we are no longer passing the original address of the buffer allocated.
Fix this by indexing through the buffer allocated to avoid incrementing
the pointer.

Fixes: 4b361cfa8624 ("mtd: core: add OTP nvmem provider support")
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-by: Michael Walle <michael@walle.cc>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210518185503.162787-1-jonathanh@nvidia.com

mtd: Create partname and partid debug files for child MTDs

Partname and partid are set by the upper driver (spi-nor) on the master
MTD. If this MTD is partitioned and CONFIG_MTD_PARTITIONED_MASTER is
disabled, the master MTD is not instantiated and partname and partid
aren't available to the userspace.

Always read the partname and partid from the master MTD, they describe
the HW, which can't differ between master and its children.

Signed-off-by: Petr Malat <oss@malat.biz>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210430065057.32018-1-oss@malat.biz

mtd: core: add OTP nvmem provider support

Flash OTP regions can already be read via user space. Some boards have
their serial number or MAC addresses stored in the OTP regions. Add
support for them being a (read-only) nvmem provider.

The API to read the OTP data is already in place. It distinguishes
between factory and user OTP, thus there are up to two different
providers.

Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210424110608.15748-6-michael@walle.cc

mtd: core: Convert sysfs sprintf/snprintf family to sysfs_emit

Use sysfs_emit instead of snprintf to avoid buf overrun,because in
sysfs_emit it strictly checks whether buf is null or buf whether
pagesize aligned, otherwise it returns an error.

Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/1618220144-33839-2-git-send-email-tiantao6@hisilicon.com

mtd: core: Constify buf in mtd_write_user_prot_reg()

The write buffer comes from user and should be const.
Constify write buffer in mtd core and across all _write_user_prot_reg()
users. cfi_cmdset_{0001, 0002} and onenand_base will pay the cost of an
explicit cast to discard the const qualifier since the beginning, since
they are using an otp_op_t function prototype that is used for both reads
and writes. mtd_dataflash and SPI NOR will benefit of the const buffer
because they are using different paths for writes and reads.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210403060931.7119-1-tudor.ambarus@microchip.com

mtd: core: add nvmem-cells compatible to parse mtd as nvmem cells

Partitions that contains the nvmem-cells compatible will register
their direct subonodes as nvmem cells and the node will be treated as a
nvmem provider.

Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Tested-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210312062830.20548-1-ansuelsmth@gmail.com

mtd: add OTP (one-time-programmable) erase ioctl

This may sound like a contradiction but some SPI-NOR flashes really
support erasing their OTP region until it is finally locked. Having the
possibility to erase an OTP region might come in handy during
development.

The ioctl argument follows the OTPLOCK style.

Signed-off-by: Michael Walle <michael@walle.cc>
Acked-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210303201819.2752-1-michael@walle.cc

mtd: mtdcore: constify name param in mtd_bdi_init

The bdi name is not modified by the function, it should be const.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210225143329.430012-1-tomas.winkler@intel.com

mtd: char: Get rid of Big MTD Lock

Get rid of central chrdev MTD lock, which prevents simultaneous operations
on completely independent physical MTD chips. Replace it with newly
introduced per-master mutex.

Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210217211845.43364-2-alexander.sverdlin@nokia.com

mtd: Handle possible -EPROBE_DEFER from parse_mtd_partitions()

There are chances that the parse_mtd_partitions() function will return
-EPROBE_DEFER in mtd_device_parse_register(). This might happen when
the dependency is not available for the parser. For instance, on SDX55
the MTD_QCOMSMEM_PARTS parser depends on the QCOM_SMEM driver to parse
the partitions defined in the shared memory region. With the current
flow, the error returned from parse_mtd_partitions() will be discarded
in favor of trying to add the fallback partition.

This will prevent the driver to end up in probe deferred pool and the
partitions won't be parsed even after the QCOM_SMEM driver is available.

Fix this issue by bailing out of mtd_device_parse_register() when
-EPROBE_DEFER error is returned from parse_mtd_partitions() function and
propagate the error code to the driver core for probing later.

Fixes: 5ac67ce36cfe ("mtd: move code adding (registering) partitions to the parse_mtd_partitions()")
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: core: Fix refcounting for unpartitioned MTDs

Apply changes to usecount also to the master partition.
Otherwise we have no refcounting at all if an MTD has no partitions.

Cc: stable@vger.kernel.org
Fixes: 46b5889cc2c5 ("mtd: implement proper partition handling")
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20201206202220.27290-1-richard@nod.at

mtd: Fix misspelled function parameter 'section'

Fixes the following W=1 kernel build warning(s):

drivers/mtd/mtdcore.c:1592: warning: Function parameter or member 'section' not described in 'mtd_ooblayout_find_eccregion'
drivers/mtd/mtdcore.c:1592: warning: Excess function parameter 'sectionp' description in 'mtd_ooblayout_find_eccregion'

Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: linux-mtd@lists.infradead.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Alexander Dahl <ada@thorsis.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20201109182206.3037326-6-lee.jones@linaro.org

bdi: initialize ->ra_pages and ->io_pages in bdi_init

Set up a readahead size by default, as very few users have a good
reason to change it. This means code, ecryptfs, and orangefs now
set up the values while they were previously missing it, while ubifs,
mtd and vboxsf manually set it to 0 to avoid readahead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: David Sterba <dsterba@suse.com> [btrfs]
Acked-by: Richard Weinberger <richard@nod.at> [ubifs, mtd]
Signed-off-by: Jens Axboe <axboe@kernel.dk>

mtd: mtdcore: Convert to DEFINE_SHOW_ATTRIBUTE

Use DEFINE_SHOW_ATTRIBUTE macro to simplify the code.

Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: set master partition panic write flag

Check and set master panic write flag so that low level drivers
can use it to take required action to ensure oops data gets written
to assigned mtdoops device partition.

Fixes: 9f897bfdd89f ("mtd: Add flag to indicate panic_write")
Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200615155134.32007-1-kdasu.kdev@gmail.com

mtd: Fix typo in mtd_ooblayout_set_databytes() description

Fix a probable copy/paste error: the function works like
mtd_ooblayout_set_bytes(), not *_get_bytes().

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/linux-mtd/20200526195633.11543-2-miquel.raynal@bootlin.com

mtd: Fix mtd not registered due to nvmem name collision

When the nvmem framework is enabled, a nvmem device is created per mtd
device/partition.

It is not uncommon that a device can have multiple mtd devices with
partitions that have the same name. Eg, when there DT overlay is allowed
and the same device with mtd is attached twice.

Under that circumstances, the mtd fails to register due to a name
duplication on the nvmem framework.

With this patch we use the mtdX name instead of the partition name,
which is unique.

[ 8.948991] sysfs: cannot create duplicate filename '/bus/nvmem/devices/Production Data'
[ 8.948992] CPU: 7 PID: 246 Comm: systemd-udevd Not tainted 5.5.0-qtec-standard #13
[ 8.948993] Hardware name: AMD Dibbler/Dibbler, BIOS 05.22.04.0019 10/26/2019
[ 8.948994] Call Trace:
[ 8.948996] dump_stack+0x50/0x70
[ 8.948998] sysfs_warn_dup.cold+0x17/0x2d
[ 8.949000] sysfs_do_create_link_sd.isra.0+0xc2/0xd0
[ 8.949002] bus_add_device+0x74/0x140
[ 8.949004] device_add+0x34b/0x850
[ 8.949006] nvmem_register.part.0+0x1bf/0x640
...
[ 8.948926] mtd mtd8: Failed to register NVMEM device

Fixes: c4dfa25ab307 ("mtd: add support for reading MTD devices via the nvmem API")
Signed-off-by: Ricardo Ribalda Delgado <ribalda@kernel.org>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

mtd: Add support for emulated SLC mode on MLC NANDs

MLC NANDs can be made a bit more reliable if we only program the lower
page of each pair. At least, this solves the paired-pages corruption
issue.

Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200503155341.16712-5-miquel.raynal@bootlin.com

bdi: remove the name field in struct backing_dev_info

The name is only printed for a not registered bdi in writeback. Use the
device name there as is more useful anyway for the unlike case that the
warning triggers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

bdi: simplify bdi_alloc

Merge the _node vs normal version and drop the superflous gfp_t argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

mtd: implement proper partition handling

Instead of collecting partitions in a flat list, create a hierarchy
within the mtd_info structure: use a partitions list to keep track of
the partitions of an MTD device (which might be itself a partition of
another MTD device), a pointer to the parent device (NULL when the MTD
device is the root one, not a partition).

By also saving directly in mtd_info the offset of the partition, we
can get rid of the mtd_part structure.

While at it, be consistent in the naming of the mtd_info structures to
ease the understanding of the new hierarchy: these structures are
usually called 'mtd', unless there are multiple instances of the same
structure. In this case, there is usually a parent/child bound so we
will call them 'parent' and 'child'.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200114090952.11232-1-miquel.raynal@bootlin.com

mtd: no need to check return value of debugfs_create functions

When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic should
never do something different based on this.

Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Marek Vasut <marek.vasut@gmail.com>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: linux-mtd@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: mtdcore: add debugfs nodes for querying the flash name and id

Currently, we don't have vfs nodes for querying the underlying flash name
and flash id. This information is important especially when we want to
know the flash detail of the defective system. In order to support the
query, we add mtd_debugfs_populate() to create two debugfs nodes
(ie. partname and partid). The upper driver can assign the pointer to
partname and partid before calling mtd_device_register().

Signed-off-by: Zhuohao Lee <zhuohao@chromium.org>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>

mtd: Add flag to indicate panic_write

Added a flag to indicate a panic_write so that low level drivers can
use it to take required action where applicable, to ensure oops data
gets written to assigned mtd device.

Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 102

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details you
should have received a copy of the gnu general public license along
with this program if not write to the free software foundation inc
51 franklin st fifth floor boston ma 02110 1301 usa

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 50 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190523091649.499889647@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mtd: Use mtd->name when registering nvmem device

With this patch, we use the mtd->name instead of concatenating the name
with '0'.

Fixes: c4dfa25ab307 ("mtd: add support for reading MTD devices via the nvmem API")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>

mtd: Remove empty lines at end of sysfs related functions

Some sysfs functions have empty stray lines after the return statement.
This patch remove those empty lines.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>

mtd: Implement mtd_{read,write}() as wrappers around mtd_{read,write}_oob()

mtd_{read,write}_oob() already take care of checking the params and
calling ->_{read,write}() or ->_{read,write}_oob() based on the
request and the operations supported by the MTD device.
No need to duplicate the logic, we can simply implement
mtd_{read,write}() as wrappers around mtd_{read,write}_oob().

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>

mtd: Fix the check on nvmem_register() ret code

Commit 20167b70c894 ("nvmem: use EOPNOTSUPP instead of ENOSYS") changed
the nvmem_register() ret code from ENOSYS to EOPNOTSUPP when
CONFIG_NVMEM is not enabled, but the check in mtd_nvmem_add() was not
adjusted accordingly.

Cc: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: Alban Bedel <albeu@free.fr>
Fixes: c4dfa25ab307 ("mtd: add support for reading MTD devices via the nvmem API")
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>
Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>

mtd: add support for reading MTD devices via the nvmem API

Allow drivers that use the nvmem API to read data stored on MTD devices.
For this the mtd devices are registered as read-only NVMEM providers.

We don't support device tree systems for now.

Signed-off-by: Alban Bedel <albeu@free.fr>
[Bartosz:
- include linux/nvmem-provider.h
- set the name of the nvmem provider
- set no_of_node to true in nvmem_config
- don't check the return value of nvmem_unregister() - it cannot fail
- tweaked the commit message]
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mtd: keep original flags for every struct mtd_info

When allocating a new partition mtd subsystem runs internal tests in the
allocate_partition(). They may result in modifying specified flags (e.g.
dropping some /features/ like write access).

Those constraints don't have to be necessary true for subpartitions. It
may happen parent partition isn't block aligned (effectively disabling
write access) while subpartition may fit blocks nicely. In such case all
checks should be run again (starting with original flags value).

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

mtd: fix Coverity integer handling issue

A Coverity robot reported an integer handling issue
(OVERFLOW_BEFORE_WIDEN) in the potentially overflowing expression:

(mtd_div_by_ws(mtd->size, mtd) - mtd_div_by_ws(offs, mtd)) *
mtd_oobavail(mtd, ops)

While such overflow will certainly never happen due to the numbers
handled, it is cleaner to fix this operation anyway.

The problem is that all the maths include 32-bit quantities, while the
result is stored in an explicit 64-bit value.

As maxooblen will just be compared with a size_t, let's change the
type of the variable to a size_t. This will not fix anything but will
clarify a bit the situation. Then, do an explicit cast to fix Coverity
warning.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

mtd: Fallback to ->_read/write() when ->_read/write_oob() is missing

Some MTD sublayers/drivers are implementing ->_read/write() and
not ->_read/write_oob().

While for NAND devices both are usually valid, for NOR devices, using
the _oob variant has no real meaning. But, as the MTD layer is supposed
to hide as much as possible the flash complexity to the user, there is
no reason to error out while it is just a matter of rewritting things
internally.

Add a fallback on mtd->_read() (resp. mtd->_write()) when the user calls
mtd_read_oob() (resp. mtd_write_oob()) while mtd->_read_oob() (resp.
mtd->_write_oob) is not implemented. There is already a fallback on the
_oob variant if the former is used.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

proc: introduce proc_create_single{,_data}

Variants of proc_create{,_data} that directly take a seq_file show
callback and drastically reduces the boilerplate code in the callers.

All trivial callers converted over.

Signed-off-by: Christoph Hellwig <hch@lst.de>

mtd: move code adding (registering) partitions to the parse_mtd_partitions()

This commit slightly simplifies the code. Every parse_mtd_partitions()
caller (out of two existing ones) had to add partitions & cleanup parser
on its own. This moves that responsibility into the function.

That change also allows dropping struct mtd_partitions argument.

There is one minor behavior change caused by this cleanup. If
parse_mtd_partitions() fails to add partitions (add_mtd_partitions()
return an error) then mtd_device_parse_register() will still try to
add (register) fallback partitions. It's a real corner case affecting
one of uncommon error paths and shouldn't cause any harm.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

mtd: Add sysfs attribute for mtd OOB available size

Expose mtd OOB available size by sysfs file. Then users can get available
OOB size by accessing /sys/class/mtd/mtdX/oobavail.

Signed-off-by: Xiaolei Li <xiaolei.li@mediatek.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

mtd: Fix some function description mismatches in mtdcore.c

In mtdcore.c, some function descriptions do not match function
definitions. Just fix these mismatches.

Signed-off-by: Xiaolei Li <xiaolei.li@mediatek.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

mtd: update documentation of mtd_device_parse_register()

In the commit 2c77c57d22adb ("mtd: move code adding master MTD out of
mtd_add_device_partitions()") behavior of mtd_device_parse_register()
has very slightly changed. It's a pretty non-significant order change
to match updated function behavior.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

mtd: Stop updating erase_info->state and calling mtd_erase_callback()

MTD users are no longer checking erase_info->state to determine if the
erase operation failed or succeeded. Moreover, mtd_erase_callback() is
now a NOP.

We can safely get rid of all mtd_erase_callback() calls and all
erase_info->state assignments. While at it, get rid of the
erase_info->state field, all MTD_ERASE_XXX definitions and the
mtd_erase_callback() function.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Richard Weinberger <richard@nod.at>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Bert Kenward <bkenward@solarflare.com>
---
Changes in v2:
- Address a few coding style issues (reported by Miquel)
- Remove comments that are no longer valid (reported by Miquel)

mtd: Stop assuming mtd_erase() is asynchronous

None of the mtd->_erase() implementations work in an asynchronous manner,
so let's simplify MTD users that call mtd_erase(). All they need to do
is check the value returned by mtd_erase() and assume that != 0 means
failure.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Richard Weinberger <richard@nod.at>

mtd: Initialize ->fail_addr early in mtd_erase()

mtd_erase() can return an error before ->fail_addr is initialized to
MTD_FAIL_ADDR_UNKNOWN. Move this initialization at the very beginning
of the function.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Richard Weinberger <richard@nod.at>

mtd: get rid of the mtd_add_device_partitions()

This simplifies code a bit by:
1) Avoiding an extra (tiny) function
2) Checking for amount of parsed (found) partitions just once
3) Avoiding clearing/filling struct mtd_partitions manually

With this commit proper functions are called directly from the
mtd_device_parse_register(). It doesn't need to use minor tricks like
memsetting struct to 0 to trigger an expected
mtd_add_device_partitions() behavior.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

mtd: move code adding master MTD out of mtd_add_device_partitions()

This change is a small cleanup of mtd_device_parse_register(). When
using MTD_PARTITIONED_MASTER it makes sure a master MTD is registered
before dealing with partitions. The advantage of this is not mixing
code handling master MTD with code handling partitions.

This commit doesn't change any behavior except from a slightly different
failure code path. The new code may need to call del_mtd_device when
something goes wrong.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

mtd: Make sure the device supports erase operations in mtd_erase()

Some devices do not implement ->_erase() or have an invalid ->erasesize
value. In this case, mtd_erase() should return -ENOTSUPP.

Note that the test is not done on the MTD_NO_ERASE flag because this
flag means 'erasing a block before writing to it is unnecessary',
not 'the erase operation is not supported'. Actually, some drivers are
setting the MTD_NO_ERASE flag but still implementing the ->_erase()
hook and setting a valid ->erasesize value.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: Miquel Raynal <miquel.raynal@free-electrons.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

mtd: Fallback to ->_read/write_oob() when ->_read/write() is missing

Some MTD sublayers/drivers are implementing ->_read/write_oob() and
provide dummy wrappers for their ->_read/write() implementations.
Let the core handle this case instead of duplicating the logic.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Miquel Raynal <miquel.raynal@free-electrons.com>
Tested-by: Ladislav Michl <ladis@linux-mips.org>

mtd: Do not allow MTD devices with inconsistent erase properties

When mtd->erasesize is 0 or mtd->_erase is NULL, that means the device
does not support the erase operation, which in turn means it should
have the MTD_NO_ERASE flag set.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: Miquel Raynal <miquel.raynal@free-electrons.com>

mtd: Fix mtd_check_oob_ops()

The mtd_check_oob_ops() helper verifies if the operation defined by the
user is correct.

Fix the check that verifies if the entire requested area exists. This
check is too restrictive and will fail anytime the last data byte of the
very last page is included in an operation.

Fixes: 5cdd929da53d ("mtd: Add sanity checks in mtd_write/read_oob()")
Signed-off-by: Miquel Raynal <miquel.raynal@free-electrons.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

mtd: Add sanity checks in mtd_write/read_oob()

Unlike what's done in mtd_read/write(), there are no checks to make sure
the parameters passed to mtd_read/write_oob() are consistent, which
forces implementers of ->_read/write_oob() to do it, which in turn leads
to code duplication and possibly errors in the logic.

Do general sanity checks, like ops fields consistency and range checking.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Peter Pan <peterpandong@micron.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

mtd: implement mtd_get_unmapped_area() using the point method

The mtd->_point method is a superset of mtd->_get_unmapped_area.
Especially in the NOR flash case, the point method ensures the flash
memory is in array (data) mode and that it will stay that way which
is precisely what callers of mtd_get_unmapped_area() would expect.

Implement mtd_get_unmapped_area() in terms of mtd->_point now that all
drivers that provided a _get_unmapped_area method also have the _point
method implemented.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Richard Weinberger <richard@nod.at>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

mtd: make device_type const

Make this const as it is only stored in the type field of a device
structure, which is const.
Done using Coccinelle.

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

mtd: create per-device and module-scope debugfs entries

Several MTD devices are using debugfs entries created in the root.
This commit provides the means for a standardized subtree, creating
one "mtd" entry at root, and one entry per device inside it, named
after the device.
The tree is registered in add_mtd_device, and released in
del_mtd_device.
Devices docg3, mtdswap and nandsim were updated to use this subtree
instead of custom ones, and their entries were prefixed with the
drivers' names.

Signed-off-by: Mario J. Rugiero <mrugiero@gmail.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: Fix check in mtd_unpoint()

The code checks that ->_point is not NULL, but we should actually check
->_unpoint value which is dereferenced a few lines after the check.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

bdi: Drop 'parent' argument from bdi_register[_va]()

Drop 'parent' argument of bdi_register() and bdi_register_va(). It is
always NULL.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>

mtd: Convert to dynamically allocated bdi infrastructure

MTD already allocates backing_dev_info dynamically. Convert it to use
generic infrastructure for this including proper refcounting. We drop
mtd->backing_dev_info as its only use was to pass mtd_bdi pointer from
one file into another and if we wanted to keep that in a clean way, we'd
have to make mtd hold and drop bdi reference as needed which seems
pointless for passing one global pointer...

CC: David Woodhouse <dwmw2@infradead.org>
CC: Brian Norris <computersforpeace@gmail.com>
CC: linux-mtd@lists.infradead.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>

mtd: fix typos in ooblayout comment blocks

- "This functions return ..." -> "This function returns ..."
- "I you want ..." -> "If you want ..."

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: Allocate bdi objects dynamically

The MTD backing dev info objects mtd_bdi was statically allocated.
So when MTD is built as a loadable module, this object fall in the
vmalloc address space.

The problem with that, is that the BDI APIs use wake_up_bit(), which calls
virt_to_page() to retrieve the memory zone of the page containing the
wait_queue to wake up, and virt_to_page() is not valid for vmalloc or
highmem addresses.

Fix this by allocating the BDI objects dynamically with kmalloc. The
objects now fall in the logical address space so that BDI APIs will
work in all cases (mtd builtin or module).

Signed-off-by: Steve Longerbeam <steve_longerbeam@mentor.com>
Signed-off-by: Jim Baxter <jim_baxter@mentor.com>
Signed-off-by: Sandeep Jain <Sandeep_Jain@mentor.com>
Reviewed-by: Richard Weinberger <richard@nod.at>
Reviewed-by: Marek Vasut <marek.vasut@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: remove unneeded initializer in mtd_ooblayout_count_bytes()

There is no need to initialize oobregion since it will be filled by
the iterator.

This function is called with mtd_ooblayout_free or mtd_ooblayout_ecc
for the iterator; both of them calls memset() to clear the oobregion.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Marek Vasut <marek.vasut@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

mtd: use min_t() to refactor mtd_ooblayout_{get, set}_bytes()

I hope this will make the code a little more readable.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Marek Vasut <marek.vasut@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

mtd: remove unneeded initializer in mtd_ooblayout_{get, set}_bytes()

There is no need to initialize oobregion and section since they will
be filled by mtd_ooblayout_find_region().

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Marek Vasut <marek.vasut@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

treewide: remove redundant #include <linux/kconfig.h>

Kernel source files need not include <linux/kconfig.h> explicitly
because the top Makefile forces to include it with:

-include $(srctree)/include/linux/kconfig.h

This commit removes explicit includes except the following:

* arch/s390/include/asm/facilities_src.h
* tools/testing/radix-tree/linux/kernel.h

These two are used for host programs.

Link: http://lkml.kernel.org/r/1473656164-11929-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mtd: introduce the mtd_pairing_scheme concept

MLC and TLC NAND devices are using NAND cells exposing more than one bit,
but instead of attaching all the bits in a given cell to a single NAND
page, each bit is usually attached to a different page. This concept is
called 'page pairing', and has significant impacts on the flash storage
usage.
The main problem showed by these devices is that interrupting a page
program operation may not only corrupt the page we are programming
but also the page it is paired with, hence the need to expose to MTD
users the pairing scheme information.

The pairing APIs allows one to query pairing information attached to a
given page (here called wunit), or the other way around (the wunit
pointed by pairing information).
It also provides several helpers to help the conversion between absolute
offsets and wunits, and query the number of pairing groups.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: Brian Norris <computersforpeace@gmail.com>

mtd: kill the nand_ecclayout struct

Now that all MTD drivers have moved to the mtd_ooblayout_ops model we can
safely remove the struct nand_ecclayout definition, and all the remaining
places where it was still used.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

mtd: create an mtd_ooblayout_ops struct to ease ECC layout definition

ECC layout definitions are currently exposed using the nand_ecclayout
struct which embeds oobfree and eccpos arrays with predefined size.
This approach was acceptable when NAND chips were providing relatively
small OOB regions, but MLC and TLC now provide OOB regions of several
hundreds of bytes, which implies a non negligible overhead for everybody
even those who only need to support legacy NANDs.

Create an mtd_ooblayout_ops interface providing the same functionality
(expose the ECC and oobfree layout) without the need for this huge
structure.

The mtd->ecclayout is now deprecated and should be replaced by the
equivalent mtd_ooblayout_ops. In the meantime we provide a wrapper around
the ->ecclayout field to ease migration to this new model.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

mtd: add mtd_ooblayout_xxx() helper functions

In order to make the ecclayout definition completely dynamic we need to
rework the way the OOB layout are defined and iterated.

Create a few mtd_ooblayout_xxx() helpers to ease OOB bytes manipulation
and hide ecclayout internals to their users.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

mtd: Hook I/O activity to the MTD LED trigger

Now that we've added the MTD LED trigger, we need
to call each I/O path to ledtrig_mtd_activity.

Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

mtd: Uninline mtd_write_oob and move it to mtdcore.c

There's no reason for having mtd_write_oob inlined in mtd.h header.
Move it to mtdcore.c where it belongs.

Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

mtd: fix cmdlinepart parser, early naming for auto-filled MTD

Commit 807f16d4db95 ("mtd: core: set some defaults when dev.parent is
set") attempted to provide some default settings for MTDs that
(a) assign the parent device and
(b) don't provide their own name or owner

However, this isn't a perfect drop-in replacement for the boilerplate
found in some drivers, because the MTD name is used by partition
parsers like cmdlinepart, but the name isn't set until add_mtd_device(),
after the parsing is completed. This means cmdlinepart sees a NULL name
and therefore will not work properly.

Fix this by moving the default name and owner assignment to be first in
the MTD registration process.

[Note: this does not fix all reported issues, particularly with NAND
drivers. Will require an additional fix for drivers/mtd/nand/]

Fixes: 807f16d4db95 ("mtd: core: set some defaults when dev.parent is set")
Reported-by: Heiko Schocher <hs@denx.de>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Cc: Heiko Schocher <hs@denx.de>
Cc: Frans Klaver <fransklaver@gmail.com>

mtd: partitions: support a cleanup callback for parsers

If partition parsers need to clean up their resources, we shouldn't
assume that all memory will fit in a single kmalloc() that the caller
can kfree(). We should allow the parser to provide a proper cleanup
routine.

Note that this means we need to keep a hold on the parser's module for a
bit longer, and release it later with mtd_part_parser_put().

Alongside this, define a default callback that we'll automatically use
if the parser doesn't provide one, so we can still retain the old
behavior.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>

mtd: partitions: pass around 'mtd_partitions' wrapper struct

For some of the core partitioning code, it helps to keep info about the
parsed partition (and who parsed them) together in one place.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: partitions: remove kmemdup()

The use of kmemdup() complicates the error handling a bit. We don't
actually need to allocate new memory, since this reference is treated as
const, and it is copied into new memory by the partition registration
code anyway. So remove it.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>

mtd: grab a reference to the MTD of_node before registering it

We now stick the device node representing the current MTD (if any) into
sysfs, so let's make sure we have a reference to it before doing that.

Suggested-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>

mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd

__GFP_WAIT has been used to identify atomic context in callers that hold
spinlocks or are in interrupts. They are expected to be high priority and
have access one of two watermarks lower than "min" which can be referred
to as the "atomic reserve". __GFP_HIGH users get access to the first
lower watermark and can be called the "high priority reserve".

Over time, callers had a requirement to not block when fallback options
were available. Some have abused __GFP_WAIT leading to a situation where
an optimisitic allocation with a fallback option can access atomic
reserves.

This patch uses __GFP_ATOMIC to identify callers that are truely atomic,
cannot sleep and have no alternative. High priority users continue to use
__GFP_HIGH. __GFP_DIRECT_RECLAIM identifies callers that can sleep and
are willing to enter direct reclaim. __GFP_KSWAPD_RECLAIM to identify
callers that want to wake kswapd for background reclaim. __GFP_WAIT is
redefined as a caller that is willing to enter direct reclaim and wake
kswapd for background reclaim.

This patch then converts a number of sites

o __GFP_ATOMIC is used by callers that are high priority and have memory
pools for those requests. GFP_ATOMIC uses this flag.

o Callers that have a limited mempool to guarantee forward progress clear
__GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall
into this category where kswapd will still be woken but atomic reserves
are not used as there is a one-entry mempool to guarantee progress.

o Callers that are checking if they are non-blocking should use the
helper gfpflags_allow_blocking() where possible. This is because
checking for __GFP_WAIT as was done historically now can trigger false
positives. Some exceptions like dm-crypt.c exist where the code intent
is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to
flag manipulations.

o Callers that built their own GFP flags instead of starting with GFP_KERNEL
and friends now also need to specify __GFP_KSWAPD_RECLAIM.

The first key hazard to watch out for is callers that removed __GFP_WAIT
and was depending on access to atomic reserves for inconspicuous reasons.
In some cases it may be appropriate for them to use __GFP_HIGH.

The second key hazard is callers that assembled their own combination of
GFP flags instead of starting with something like GFP_KERNEL. They may
now wish to specify __GFP_KSWAPD_RECLAIM. It's almost certainly harmless
if it's missed in most cases as other activity will wake kswapd.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mtd: don't WARN about overloaded users of mtd->reboot_notifier.notifier_call

There are multiple types of users of mtd->reboot_notifier.notifier_call:

(1) A while back, the cfi_cmdset_000{1,2} chip drivers implemented a
reboot notifier to (on a best effort basis) attempt to reset their flash
chips before rebooting.

(2) More recently, we implemented a common _reboot() hook so that MTD
drivers (particularly, NAND flash) could better halt I/O operations
without having to reimplement the same notifier boilerplate.

Currently, the WARN_ONCE() condition here was written to handle (2), but
at the same time it mis-diagnosed case (1) as an already-registered MTD.
Let's fix this by having the WARN_ONCE() condition better imitate the
condition that immediately follows it. (Wow, I don't know how I missed
that one.)

(Side note: Unfortunately, we can't yet combine the reboot notifier code
for (1) and (2) with a patch like [1], because some users of (1) also
use mtdconcat, and so the mtd_info struct from cfi_cmdset_000{1,2} won't
actually get registered with mtdcore, and therefore their reboot
notifier won't get registered.)

[1] http://patchwork.ozlabs.org/patch/417981/

Suggested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Cc: Jesper Nilsson <jespern@axis.com>
Cc: linux-cris-kernel@axis.com
Tested-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: mtdpart: Do not fail mtd probe when parsing partitions fails

Due to wrong assumption in ofpart ofpart fails on Exynos on SPI chips
with no partitions because the subnode containing controller data
confuses the ofpart parser.

Thus compiling in ofpart support automatically fails probing any SPI NOR
flash without partitions on Exynos.

Compiling in a partitioning scheme should not cause probe of otherwise
valid device to fail.

Instead, let's do the following:
* try parsers until one succeeds
* if no parser succeeds, report the first error we saw
* even in the failure case, allow MTD to probe, with fallback
partitions or no partitions at all -- the master device will still be
registered

Issue report and comments initially by Michal Suchanek.

Reported-by: Michal Suchanek <hramrach@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: warn when registering the same master many times

When CONFIG_MTD_PARTITIONED_MASTER=y, it is fatal to call
mtd_device_parse_register() twice on the same MTD, as we try to register
the same device/kobject multipile times.

When CONFIG_MTD_PARTITIONED_MASTER=n, calling
mtd_device_parse_register() is more of just a nuisance, as we can mostly
navigate around any conflicting actions.

But anyway, doing so is a Bad Thing (TM), and we should complain loudly
for any drivers that try to do this.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Richard Weinberger <richard@nod.at>

mtd: fixup corner case error handling in mtd_device_parse_register()

Since commit 3efe41be224c ("mtd: implement common reboot notifier
boilerplate"), we might try to register a reboot notifier for an MTD
that failed to register. Let's avoid this by making the error path
clearer.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Richard Weinberger <richard@nod.at>

mtd: core: set some defaults when dev.parent is set

If a parent device is set, add_mtd_device() has enough knowledge to fill
in some sane default values for the module name and owner. Do so if they
aren't already set.

Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: core: tone down suggestion that dev.parent should be set

add_mtd_device() has a comment suggesting that the caller should have
set dev.parent. This is required to have the parent device symlink show
up in sysfs, but not for proper operation of the mtd device itself.
Currently we have five drivers registering mtd devices during module
initialization, so they don't actually provide a parent device to link
to. That means we cannot WARN_ON() here, as it would trigger false
positives.

Make the comment a bit less firm in its assertion that dev.parent should
be set.

Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: Destroy mtd_idr on module_exit

Destroy mtd_idr on module_exit, reclaiming the allocated memory.

This was detected by the following semantic patch (written by Luis Rodriguez
<mcgrof@suse.com>)
<SmPL>
@ defines_module_init @
declarer name module_init, module_exit;
declarer name DEFINE_IDR;
identifier init;
@@

module_init(init);

@ defines_module_exit @
identifier exit;
@@

module_exit(exit);

@ declares_idr depends on defines_module_init && defines_module_exit @
identifier idr;
@@

DEFINE_IDR(idr);

@ on_exit_calls_destroy depends on declares_idr && defines_module_exit @
identifier declares_idr.idr, defines_module_exit.exit;
@@

exit(void)
{
...
idr_destroy(&idr);
...
}

@ missing_module_idr_destroy depends on declares_idr && defines_module_exit && !on_exit_calls_destroy @
identifier declares_idr.idr, defines_module_exit.exit;
@@

exit(void)
{
...
+idr_destroy(&idr);
}
</SmPL>

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: propagate error codes from add_mtd_device()

It makes more sense to return error statuses, not 1/0.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Richard Weinberger <richard@nod.at>

mtd: Switch to PM ops

Use dev_pm_ops instead of the legacy suspend/resume callbacks for the MTD
class suspend and resume operations.

While we are at it slightly reorder things to avoid the need for forward
declarations.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: part: Create the master device node when partitioned

For many use cases, it helps to have a device node for the entire
MTD device as well as device nodes for the individual partitions.
For example, this allows querying the entire device's properties.
A common idiom is to create an additional partition which spans
over the whole device.

This patch makes a config option, CONFIG_MTD_PARTITIONED_MASTER,
which makes the master partition present even when the device is
partitioned. This isn't turned on by default since it presents
a backwards-incompatible device numbering.

The patch also makes the parent of a partition device be the master,
if the config flag is set, now that the master is a full device.

Signed-off-by: Dan Ehrenberg <dehrenberg@chromium.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: avoid registering reboot notifier twice

Calling mtd_device_parse_register with the same mtd_info
(e.g. registering several partitions on a single device)
would add the same reboot notifier twice, causing an
infinte loop in notifier_chain_register during boot up.

Signed-off-by: Niklas Cassel <nks@flawful.org>
[Brian: add FIXME comments]
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: export new mtd_mmap_capabilities

The recently added mtd_mmap_capabilities can be used from loadable
modules, in particular romfs, but is not exported, so we get

ERROR: "mtd_mmap_capabilities" [fs/romfs/romfs.ko] undefined!

This adds the missing export.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: b4caecd48005f ("fs: introduce f_op->mmap_capabilities for nommu mmap support")
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

fs: introduce f_op->mmap_capabilities for nommu mmap support

Since "BDI: Provide backing device capability information [try #3]" the
backing_dev_info structure also provides flags for the kind of mmap
operation available in a nommu environment, which is entirely unrelated
to it's original purpose.

Introduce a new nommu-only file operation to provide this information to
the nommu mmap code instead. Splitting this from the backing_dev_info
structure allows to remove lots of backing_dev_info instance that aren't
otherwise needed, and entirely gets rid of the concept of providing a
backing_dev_info for a character device. It also removes the need for
the mtd_inodefs filesystem.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tejun Heo <tj@kernel.org>
Acked-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

mtd: implement common reboot notifier boilerplate

cfi_cmdset_000{1,2}.c already implement their own reboot notifiers, and
we're going to add one for NAND. Let's put the boilerplate in one place.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Tested-by: Scott Branden <sbranden@broadcom.com>

mtd: remove dead non-char logic

MTD used to allow compiling out character device support. This was
dropped in the following commit, but some of the accompanying logic was
never dropped:

commit 660685d9d1b4730f0b5ca97fa95f272f99c63bce
Author: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Date: Thu Mar 14 13:27:40 2013 +0200

mtd: merge mtdchar module with mtdcore

The weird logic was flagged by Coverity.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

mtd: correct upper bounds check for mtd_*() APIs

When checking the upper boundary (i.e., whether an address is higher
than the maximum size of the MTD), we should be doing an inclusive check
(greater or equal). For instance, an address of 16MB (0x1000000) on a
16MB device is invalid.

The strengthening of this bounds check is redundant for those which
already have a address+length check and ensure that the length is
non-zero, but let's just fix them all, for completeness.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: Introduce mtd_block_isreserved()

In addition to mtd_block_isbad(), which checks if a block is bad or
reserved, it's needed to check if a block is reserved only (but not
bad). This commit adds an MTD interface for it, in a similar fashion to
mtd_block_isbad().

While here, fix mtd_block_isbad() so the out-of-bounds checking is done
before the callback check.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Pekon Gupta <pekon@ti.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: Add sysfs attributes to expose the ECC stats fields

These new sysfs device attributes allow us to retrieve the ECC and bad
block stats by poking a sysfs file, which is often more convenient than
using the ioctl.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Pekon Gupta <pekon@ti.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: Fix the behavior of OTP write if there is not enough room for data

If a write to one time programmable memory (OTP) hits the end of this
memory area, no more data can be written. The count variable in
mtdchar_write() in drivers/mtd/mtdchar.c is not decreased anymore.
We are trapped in the loop forever, mtdchar_write() will never return
in this case.

The desired behavior of a write in such a case is described in [1]:
- Try to write as much data as possible, truncate the write to fit into
the available memory and return the number of bytes that actually
have been written.
- If no data could be written at all, return -ENOSPC.

This patch fixes the behavior of OTP write if there is not enough space
for all data:

1) mtd_write_user_prot_reg() in drivers/mtd/mtdcore.c is modified to
return -ENOSPC if no data could be written at all.
2) mtdchar_write() is modified to handle -ENOSPC correctly. Exit if a
write returned -ENOSPC and yield the correct return value, either
then number of bytes that could be written, or -ENOSPC, if no data
could be written at all.

Furthermore the patch harmonizes the behavior of the OTP memory write
in drivers/mtd/devices/mtd_dataflash.c with the other implementations
and the requirements from [1]. Instead of returning -EINVAL if the data
does not fit into the OTP memory, we try to write as much data as
possible/truncate the write.

[1] http://pubs.opengroup.org/onlinepubs/9699919799/functions/write.html

Signed-off-by: Christian Riesch <christian.riesch@omicron.at>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: Add a retlen parameter to _get_{fact,user}_prot_info

Signed-off-by: Christian Riesch <christian.riesch@omicron.at>
Cc: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: convert to use ATTRIBUTE_GROUPS

Use new ATTRIBUTE_GROUPS macro to declare attribute groups.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: remove duplicated include from mtdcore.c

Remove duplicated include.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: Move major number definitions to major.h

This patch moves the char and block major number definitions
to major.h to be with the rest of the major numbers.
While doing this, include major.h in the files that need it.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: add MTD_MLCNANDFLASH case for mtd_type_show()

The current mtd_type_show() misses the MTD_MLCNANDFLASH case.
This patch adds the case for it, and also updates the ABI.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: add a new sys node to show the ecc step size

Add a new sys node to show the ecc step size.
The application then can uses this node to get the ecc step
size.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

drivers: avoid format string in dev_set_name

Calling dev_set_name with a single paramter causes it to be handled as a
format string. Many callers are passing potentially dynamic string
content, so use "%s" in those cases to avoid any potential accidents,
including wrappers like device_create*() and bdi_register().

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Include missing linux/slab.h inclusions

Include missing linux/slab.h inclusions where the source file is currently
expecting to get kmalloc() and co. through linux/proc_fs.h.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cc: linux-s390@vger.kernel.org
cc: sparclinux@vger.kernel.org
cc: linux-efi@vger.kernel.org
cc: linux-mtd@lists.infradead.org
cc: devel@driverdev.osuosl.org
cc: x86@kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

mtd: merge mtdchar module with mtdcore

The MTD subsystem has historically tried to be as configurable as possible. The
side-effect of this is that its configuration menu is rather large, and we are
gradually shrinking it. For example, we recently merged partitions support with
the mtdcore.

This patch does the next step - it merges the mtdchar module to mtdcore. And in
this case this is not only about eliminating too fine-grained separation and
simplifying the configuration menu. This is also about eliminating seemingly
useless kernel module.

Indeed, mtdchar is a module that allows user-space making use of MTD devices
via /dev/mtd* character devices. If users do not enable it, they simply cannot
use MTD devices at all. They cannot read or write the flash contents. Is it a
sane and useful setup? I believe not. And everyone just enables mtdchar.

Having mtdchar separate is also a little bit harmful. People sometimes miss the
fact that they need to enable an additional configuration option to have
user-space MTD interfaces, and then they wonder why on earth the kernel does
not allow using the flash? They spend time asking around.

Thus, let's just get rid of this module and make it part of mtd core.

Note, mtdchar had additional configuration option to enable OTP interfaces,
which are present on some flashes. I removed that option as well - it saves a
really tiny amount space.

[dwmw2: Strictly speaking, you can mount file systems on MTD devices just
fine without the mtdchar (or mtdblock) devices; you just can't do
other manipulations directly on the underlying device. But still I
agree that it makes sense to make this unconditional. And Yay! we
get to kill off an instance of checking CONFIG_foo_MODULE, which is
an abomination that should never happen.]

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: mtdcore: remove few useless #ifdef's

Remove a couple of useles '#ifdef CONFIG_PROC_FS's around procfs functions
which anyway turn into empty function in 'proc_fs.h' file when CONFIG_PROC_FS
is not defined.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: add 'const' qualifier to a couple of register functions

'mtd_device_parse_register()' and 'parse_mtd_partitions()' functions accept a
an array of character pointers. These functions modify neither the pointers nor
the characters they point to. The characters are actually names of the MTD
parsers.

At the moment, the argument type is 'const char **', which means that only the
names of the parsers are constant. Let's turn the argument type into 'const
char * const *', which means that both names and the pointers which point to
them are constant.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Revert "revert "Revert "mm: remove __GFP_NO_KSWAPD""" and associated damage

This reverts commits a50915394f1fc02c2861d3b7ce7014788aa5066e and
d7c3b937bdf45f0b844400b7bf6fd3ed50bac604.

This is a revert of a revert of a revert. In addition, it reverts the
even older i915 change to stop using the __GFP_NO_KSWAPD flag due to the
original commits in linux-next.

It turns out that the original patch really was bogus, and that the
original revert was the correct thing to do after all. We thought we
had fixed the problem, and then reverted the revert, but the problem
really is fundamental: waking up kswapd simply isn't the right thing to
do, and direct reclaim sometimes simply _is_ the right thing to do.

When certain allocations fail, we simply should try some direct reclaim,
and if that fails, fail the allocation. That's the right thing to do
for THP allocations, which can easily fail, and the GPU allocations want
to do that too.

So starting kswapd is sometimes simply wrong, and removing the flag that
said "don't start kswapd" was a mistake. Let's hope we never revisit
this mistake again - and certainly not this many times ;)

Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

revert "Revert "mm: remove __GFP_NO_KSWAPD""

It apepars that this patch was innocent, and we hope that "mm: avoid
waking kswapd for THP allocations when compaction is deferred or
contended" will fix the final kswapd-spinning cause.

Cc: Zdenek Kabelac <zkabelac@redhat.com>
Cc: Seth Jennings <sjenning@linux.vnet.ibm.com>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Robert Jennings <rcj@linux.vnet.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Revert "mm: remove __GFP_NO_KSWAPD"

With "mm: vmscan: scale number of pages reclaimed by reclaim/compaction
based on failures" reverted, Zdenek Kabelac reported the following

Hmm, so it's just took longer to hit the problem and observe
kswapd0 spinning on my CPU again - it's not as endless like before -
but still it easily eats minutes - it helps to turn off Firefox
or TB (memory hungry apps) so kswapd0 stops soon - and restart
those apps again. (And I still have like >1GB of cached memory)

kswapd0 R running task 0 30 2 0x00000000
Call Trace:
preempt_schedule+0x42/0x60
_raw_spin_unlock+0x55/0x60
put_super+0x31/0x40
drop_super+0x22/0x30
prune_super+0x149/0x1b0
shrink_slab+0xba/0x510

The sysrq+m indicates the system has no swap so it'll never reclaim
anonymous pages as part of reclaim/compaction. That is one part of the
problem but not the root cause as file-backed pages could also be
reclaimed.

The likely underlying problem is that kswapd is woken up or kept awake
for each THP allocation request in the page allocator slow path.

If compaction fails for the requesting process then compaction will be
deferred for a time and direct reclaim is avoided. However, if there
are a storm of THP requests that are simply rejected, it will still be
the the case that kswapd is awake for a prolonged period of time as
pgdat->kswapd_max_order is updated each time. This is noticed by the
main kswapd() loop and it will not call kswapd_try_to_sleep(). Instead
it will loopp, shrinking a small number of pages and calling
shrink_slab() on each iteration.

The temptation is to supply a patch that checks if kswapd was woken for
THP and if so ignore pgdat->kswapd_max_order but it'll be a hack and not
backed up by proper testing. As 3.7 is very close to release and this
is not a bug we should release with, a safer path is to revert "mm:
remove __GFP_NO_KSWAPD" for now and revisit it with the view to ironing
out the balance_pgdat() logic in general.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Zdenek Kabelac <zkabelac@redhat.com>
Cc: Seth Jennings <sjenning@linux.vnet.ibm.com>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Robert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: remove __GFP_NO_KSWAPD

When transparent huge pages were introduced, memory compaction and swap
storms were an issue, and the kernel had to be careful to not make THP
allocations cause pageout or compaction.

Now that we have working compaction deferral, kswapd is smart enough to
invoke compaction and the quadratic behaviour around isolate_free_pages
has been fixed, it should be safe to remove __GFP_NO_KSWAPD.

[minchan@kernel.org: Comment fix]
[mgorman@suse.de: Avoid direct reclaim for deferred compaction]
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mtd: check for max_bitflips in mtd_read_oob()

mtd_read_oob() has some unexpected similarities to mtd_read(). For
instance, when ops->datbuf != NULL, nand_base.c might return max_bitflips;
however, when ops->datbuf == NULL, nand_base's code potentially could
return -EUCLEAN (no in-tree drivers do this yet). In any case where the
driver might return max_bitflips, we should translate this into an
appropriate return code using the bitflip_threshold.

Essentially, mtd_read_oob() duplicates the logic from mtd_read().

This prevents users of mtd_read_oob() from receiving a positive return
value (i.e., from max_bitflips) and interpreting it as an unknown error.

Artem: amend comments.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Mike Dunn <mikedunn@newsguy.com>
Reviewed-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: move mtd_read_oob() definition out of mtd.h

mtd_read_oob() will be expanded a little, so don't leave it in the header
as a static inline function.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: driver _read() returns max_bitflips; mtd_read() returns -EUCLEAN

The drivers' _read() method, absent an error, returns a non-negative integer
indicating the maximum number of bit errors that were corrected in any one
region comprising an ecc step. MTD returns -EUCLEAN if this is >=
bitflip_threshold, 0 otherwise. If bitflip_threshold is zero, the comparison is
not made since these devices lack ECC and always return zero in the non-error
case (thanks Brian)¹. Note that this is a subtle change to the driver
interface.

This and the preceding patches in this set were tested with ubi on top of the
nandsim and docg4 devices, running the ubi test io_basic from mtd-utils.

¹ http://lists.infradead.org/pipermail/linux-mtd/2012-March/040468.html

Signed-off-by: Mike Dunn <mikedunn@newsguy.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Brian Norris <computersforpeace@gmail.com>
Ivan Djelic <ivan.djelic@parrot.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: bitflip_threshold added to mtd_info and sysfs

An element 'bitflip_threshold' is added to struct mtd_info, and also exposed as
a read/write variable in sysfs. This will be used to determine whether or not
mtd_read() returns -EUCLEAN or 0 (absent a hard error). If the driver leaves it
as zero, mtd will set it to a default value of ecc_strength.

This v2 adds the line that propagates bitflip_threshold from the master to the
partitions - thanks Ivan¹.

¹ http://lists.infradead.org/pipermail/linux-mtd/2012-April/040900.html

Signed-off-by: Mike Dunn <mikedunn@newsguy.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: expose ecc_strength through sysfs

ecc_strength element of struct mtd_info is exposed as a read-only variable in
sysfs.

Signed-off-by: Mike Dunn <mikedunn@newsguy.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: unify initialization of erase_info->fail_addr

Initialization of 'erase_info->fail_addr' to MTD_FAIL_ADDR_UNKNOWN prior
erase operation is duplicated accross several MTD drivers, and also taken
care of by some MTD users as well.

Harmonize it: initialize 'fail_addr' within 'mtd_erase()' interface.

Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: check for zero length in OTP functions

This patch changes all the OTP functions like 'mtd_get_fact_prot_info()' and
makes them return zero immediately if the input 'len' parameter is 0. This is
not really needed currently, but most of the other functions do this, and it is
just consistent to do the same in the OTP functions.

This patch also moves the OTP functions from the header file to mtdcore.c
because they become a bit too big for being inlined.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: move zero length verification to MTD API functions

In many places in drivers we verify for the zero length, but this is very
inconsistent across drivers. This is obviously the right thing to do, though.
This patch moves the check to the MTD API functions instead and removes a lot
of duplication.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Reviewed-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: harmonize mtd_point interface implementation

Some MTD drivers return -EINVAL if the 'phys' parameter is not NULL, trying to
convey that they cannot return the physical address. However, this is not very
logical because they still can return the virtual address ('virt'). But some
drivers (lpddr) just ignore the 'phys' parameter instead, which is a more
logical thing to do.

Let's harmonize this and:

1. Always initialize 'virt' and 'phys' to 'NULL' in 'mtd_point()'.
2. Do not return an error if the physical address cannot be found.

So as a result, all drivers will set 'phys' to 'NULL' if it is not supported.
None of the 'mtd_point()' users use 'phys' anyway, so this should not break
anything. I guess we could also just delete this parameter later.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: remove retlen zeroing duplication

The MTD API function now zero the 'retlen' parameter before calling
the driver's method — do not do this again in drivers. This removes
duplicated '*retlen = 0' assignent from the following methods:

'mtd_point()'
'mtd_read()'
'mtd_write()'
'mtd_writev()'
'mtd_panic_write()'

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: remove R/O checking duplication

Many drivers check whether the partition is R/O and return -EROFS if yes.
Let's stop having duplicated checks and move them to the API functions
instead.

And again a bit of noise - deleted few too sparse newlines, sorry.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: add offset and length checks to the API function

Add verification of the offset and length to MTD API functions and verify that
MTD device offset and length are within MTD device size.

The modified API functions are:

'mtd_erase()'
'mtd_point()'
'mtd_unpoint()'
'mtd_get_unmapped_area()'
'mtd_read()'
'mtd_write()'
'mtd_panic_write()'
'mtd_lock()'
'mtd_unlock()'
'mtd_is_locked()'
'mtd_block_isbad()'
'mtd_block_markbad()'

This patch also uninlines these functions and exports in mtdcore.c because they
are not performance-critical and do not have to be inlined.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: mtdcore: remove unnecessary mtd->resume check

We don't need to to check for mtd->resume before calling mtd_resume().
mtd_resume() should take care of that.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: add leading underscore to all mtd functions

This patch renames all MTD functions by adding a "_" prefix:

mtd->erase -> mtd->_erase
mtd->read_oob -> mtd->_read_oob
...

The reason is that we are re-working the MTD API and from now on it is
an error to use MTD function pointers directly - we have a corresponding
API call for every pointer. By adding a leading "_" we achieve the following:

1. Make sure we convert every direct pointer users
2. A leading "_" suggests that this interface is internal and it becomes
less likely that people will use them directly
3. Make sure all the out-of-tree modules stop compiling and the owners
spot the big API change and amend them.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: mtdcore: Fix build warning when CONFIG_MTD_CHAR is not defined

Fix the following build warning:

drivers/mtd/mtdcore.c: In function ‘mtd_release’:
drivers/mtd/mtdcore.c:110: warning: unused variable ‘mtd’

This happens when neither CONFIG_MTD_CHAR nor CONFIG_MTD_CHAR_MODULE are defined.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: fix MTD suspend

Commits 3fe4bae88460869a8e553397cd9057a4ee7ca341 and
079c985e7a6f4ce60f931cebfdd5ee3c3 broke MTD suspend in 2 ways:

1. When the '->suspend' method is not present, we return -EOPNOTSUPP, but
the callers of 'mtd_suspend()' expects 0 instead.
2. Checking of the 'mtd' parameter against NULL has been incorrectly removed
in 'mtd_cls_suspend()'.

This patch fixes the breakages. This has been found, analyzed, reported
and tested by Rafael J. Wysocki <rjw@sisk.pl>.

Note, this patch is not needed in the stable tree because it causes a
regression introduced during the v3.3 merge window.

Reported-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: do not use mtd->suspend and mtd->resume directly

Just call the 'mtd_suspend()' and 'mtd_resume()' - they will do nothing
if the operation is not defined.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: do not use mtd->lock, unlock and is_locked directly

Instead, call the corresponding MTD API function which will return
'-EOPNOTSUPP' if the operation is not supported.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: harmonize mtd_writev usage

This patch makes the 'mtd_writev()' function more usable and logical. We first
teach it to fall-back to the 'default_mtd_writev()' function if the MTD driver
does not define its own '->writev()' method. Then we make block2mtd and JFFS2
just 'mtd_writev()' instead of 'default_mtd_writev()' function. This means we
can now stop exporting 'default_mtd_writev()' and instead, export
'mtd_writev()'. This is much cleaner and more logical, as well as allows us to
get read of another direct 'mtd->writev' access in JFFS2.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: mtdcore: export symbols cleanup

The mtdcore.c file is a bit inconsistent - some EXPORT_SYMBOL_GPL declarations
follow the corresponding functions, some are placed at the end. This patch
harmonizes the file so that EXPORT_SYMBOL_GPL declarations follow the
corresponding function.

It also removes few extra newlines and trailing white-spaces.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: clean-up the default_mtd_writev function

1. Teach 'mtd_write()' function to return '-EROFS' if the write method
is undefined, and remove the corresponding check from
'default_mtd_writev()'.
2. Do not test 'retlen' for NULL - it cannot be NULL.
3. Few minor coding stile clean-ups.
4. Add a kerneldoc comment

Additionally, minor fixes to the kerneldoc comments of the neighbor function.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: kill dev_to_mtd helper

... since it is not needed because the generic 'dev_get_drvdata()' can be
used instead.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: introduce mtd_resume interface

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: introduce mtd_suspend interface

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: introduce mtd_unlock interface

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: introduce mtd_write interface

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: check parts pointer before using it

The code has the check for parts but it called after kmemdup,
kmemdup(parts, sizeof(*parts) * nr_parts,...)
if (!parts)
return -ENOMEM

In fact, we need check parts before safely using it.
and we also need check the real_parts to make sure kmemdup
allocation sucessfully.

Signed-off-by: Jason Liu <jason.hui@linaro.org>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>

mtd: spelling fixes

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>

mtd: replace DEBUG() with pr_debug()

Start moving away from the MTD_DEBUG_LEVEL messages. The dynamic
debugging feature is a generic kernel feature that provides more
flexibility.

(See Documentation/dynamic-debug-howto.txt)

Also fix some punctuation, indentation, and capitalization that went
along with the affected lines.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>

mtd: drop mtd_device_register

mtd_device_register() is a limited version of mtd_device_parse_register.
Replace it with macro calling mtd_device_parse_register().

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

mtd: abstract last MTD partition parser argument

Encapsulate last MTD partition parser argument into a separate
structure. Currently it holds only 'origin' field for RedBoot parser,
but will be extended in future to contain at least device_node for OF
devices.

Amended commentary to make kerneldoc happy

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Artem Bityutskiy <dedekind1@gmail.com>

mtd: add new API for handling MTD registration

Lots (nearly all) mtd drivers contain nearly the similar code that
calls parse_mtd_partitions, provides some platform-default values, if
parsing fails, and registers mtd device.

This is an aim to provide single implementation of this scenario:
mtd_device_parse_register() which will handle all this parsing and
defaults.

Artem: amended comments

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

mtd: remove add_mtd_partitions, add_mtd_device and friends

These symbols are replaced with mtd_device_register() (and removal with
mtd_device_unregister()) for public registration.

Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: introduce mtd_device_(un)register()

To prepare for the removal of add_mtd_device and add_mtd_partitions(),
introduce mtd_device_register(). This will create partitions if they
are supplied or register the whole device if there are no partitions.

Once all drivers are converted to use mtd_device_register(),
add_mtd_device() and add_mtd_partitions() will be made internal only.

v2: move kerneldoc to implementation file and fixup some kerneldoc
warnings.

Artem: tweak comments: remove junk tabs, use dots consistently.

Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd:fix the bad format in the mtdcore.c

Remove the spare spaces in the head of the lines.

Signed-off-by: Wanlong Gao <wanlong.gao@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: simplify get_mtd_device_nm function

'get_mtd_device_nm()' has a piece of code which equivalent to what
'__get_mtd_device()' does - remove this duplicated code and use
''__get_mtd_device()' instead.

Artem: changed commit message.
Artem: while on it, remove an unnecessary extra empty line

Signed-off-by: Wanlong Gao <wanlong.gao@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: convert to seq_file interface

->read_proc interface is going away, switch to seq_file.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: create function to perform large allocations

Introduce a common function to handle large, contiguous kmalloc buffer
allocations by exponentially backing off on the size of the requested
kernel transfer buffer until it succeeds or until the requested
transfer buffer size falls below the page size.

This helps ensure the operation can succeed under low-memory, highly-
fragmented situations albeit somewhat more slowly.

Artem: so this patch solves the problem that the kernel tries to kmalloc too
large buffers, which (a) may fail and does fail - people complain about this,
and (b) slows down the system in case of high memory fragmentation, because
the kernel starts dropping caches, writing back, swapping, etc. But we do not
really have to allocate a lot of memory to do the I/O, we may do this even with
as little as one min. I/O unit (NAND page) of RAM. So the idea of this patch is
that if the user asks to read or write a lot, we try to kmalloc a lot, with GFP
flags which make the kernel _not_ drop caches, etc. If we can allocate it - good,
if not - we try to allocate twice as less, and so on, until we reach the min.
I/O unit size, which is our last resort allocation and use the normal
GFP_KERNEL flag.

Artem: re-write the allocation function so that it makes sure the allocated
buffer is aligned to the min. I/O size of the flash.

Signed-off-by: Grant Erickson <marathon96@gmail.com>
Tested-by: Ben Gardiner <bengardiner@nanometrics.ca>
Tested-by: Stefano Babic <sbabic@denx.de>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: local symbols should be static

The three backing_dev_info symbols are only used in this file and
should be static.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: Remove obsolete <mtd/compatmac.h> include

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: Update copyright notices

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

mtd: update gfp/slab.h includes

Implicit slab.h inclusion via percpu.h is about to go away. Make sure
gfp.h or slab.h is included as necessary.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: ensure that bdi entries are properly initialized and registered

They will be holding dirty inodes and be responsible for flushing
them out, so they need to be setup properly.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Move mtd_bdi_*mappable to mtdcore.c

Removes one .h and one .c file that are never used outside of
mtdcore.c.

Signed-off-by: Joern Engel <joern@logfs.org>

Edited to remove on leftover debug define.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

mtd: call the remove notifiers before assuming it is in use

Now that mtd block common layer is prepared for proper hotplug support,
enable it here

Now all users of the mtd device have a chance to put the mtd device
when they are notified to do so, and they have to do so to make hotplug work.

[dwmw2: There's more work to be done to fix hotplug in the general case, but
this is a reasonable start]

Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: create unlocked versions of {get,put}_mtd_device

Use these only if you know that you already hold mtd_table_mutex

Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: Replace static array of devices with an idr structure

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: Introduce and use iteration macro for reading the MTD device table

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: ensure index is positive

The index is signed, make sure it is not negative
when we read the array element.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

driver model: constify attribute groups

Let attribute group vectors be declared "const". We'd
like to let most attribute metadata live in read-only
sections... this is a start.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

mtd: make few symbols static

Make mtd_group and mtd_groups static since they are only used in this
file.

[Amended by Artem Bityutskiy]

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: fix the conversion from dev to mtd_info

The patch fixes a bug when converting dev to mtd_info by using the
drvdata of the dev, the previous code used
container_of(dev, struct mtd_info, dev), but won't work for the mtdXro
devices as they created without being contained inside mtd_info structure.

Signed-off-by: Saeed Bishara <saeed@marvell.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

[MTD] Restore suspend/resume support for mtd devices

This is intended to suspend/resume the _chip_, while we leave board
drivers to handle their own suspend/resume for the controller.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: expose subpage size via sysfs

MTD has got sysfs support in 2.6.30-rc1. But subpage size is not
exposed there - do this.

UBI utilities badly need this parameter. At the moment there is
no way to get subpage size - ioctls do not return it. And we
just got sysfs support, so we can easilly extend it with this
additional parameter.

This can be merged late in the development cycle because:
1. sysfs support has been just added - there are no users for
it so far, even.
2. UBI utilities really need this parameter, and it is better
not to delay this.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: mtd in mtd_release is unused without CONFIG_MTD_CHAR

drivers/mtd/mtdcore.c: In function 'mtd_release':
drivers/mtd/mtdcore.c:51: warning: unused variable 'mtd'

[akpm: make it actually build]
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

[MTD] sysfs support should not depend on CONFIG_PROC_FS

Move the driver model init code out of the "#ifdef CONFIG_PROC_FS"
block.

Tested with both values of CONFIG_PROC_FS . Tested with CONFIG_MTD=m .

Issue was reported here: http://lkml.org/lkml/2009/4/4/107

Signed-off-by: Kevin Cernekee <kpc.mtd@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

[MTD] driver model updates (part 2)

1) Add more sysfs attributes: flags, size, erasesize, writesize,
oobsize, numeraseregions, name

2) Move core_initcall() code into init_mtd(). The original approach
does not work if CONFIG_MTD=m .

3) Add device_unregister() in del_mtd_device() so that devices get
removed from sysfs as each driver is unloaded.

Signed-off-by: Kevin Cernekee <kpc.mtd@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

[MTD] driver model updates

Update driver model support in the MTD framework, so it fits
better into the current udev-based hotplug framework:

- Each mtd_info now has a device node. MTD drivers should set
the dev.parent field to point to the physical device, before
setting up partitions or otherwise declaring MTDs.

- Those device nodes always map to /sys/class/mtdX device nodes,
which no longer depend on MTD_CHARDEV.

- Those mtdX sysfs nodes have a "starter set" of attributes;
it's not yet sufficient to replace /proc/mtd.

- Enabling MTD_CHARDEV provides /sys/class/mtdXro/ nodes and the
/sys/class/mtd*/dev attributes (for udev, mdev, etc).

- Include a MODULE_ALIAS_CHARDEV_MAJOR macro. It'll work with
udev creating the /dev/mtd* nodes, not just a static rootfs.

So the sysfs structure is pretty much what you'd expect, except
that readonly chardev nodes are a bit quirky.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

NOMMU: Present backing device capabilities for MTD chardevs

Present backing device capabilities for MTD character device files to allow
NOMMU mmap to do direct mapping where possible.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Bernd Schmidt <bernd.schmidt@analog.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

[MTD] update internal API to support 64-bit device size

MTD internal API presently uses 32-bit values to represent
device size. This patch updates them to 64-bits but leaves
the external API unchanged. Extending the external API
is a separate issue for several reasons. First, no one
needs it at the moment. Secondly, whether the implementation
is done with IOCTLs, sysfs or both is still debated. Thirdly
external API changes require the internal API to be accepted
first.

Note that although the MTD API will be able to support 64-bit
device sizes, existing drivers do not and are not required
to do so, although NAND base has been updated.

In general, changing from 32-bit to 64-bit values cause little
or no changes to the majority of the code with the following
exceptions:
- printk message formats
- division and modulus of 64-bit values
- NAND base support
- 32-bit local variables used by mtdpart and mtdconcat
- naughtily assuming one structure maps to another
in MEMERASE ioctl

Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

[MTD] Use list_for_each_entry[_safe] where appropriate.

Janitorial work to remove temporary pointers and make some functions a bit
more readable.

Signed-off-by: Chris Malley <mail@chrismalley.co.uk>
Reviewed-By: Jörn Engel <joern@logfs.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

MTD/JFFS2: remove CVS keywords

Once upon a time, the MTD repository was using CVS.

This patch therefore removes all usages of the no longer updated CVS
keywords from the MTD code.

This also includes code that printed them to the user.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

[MTD] use list_for_each_entry() in del_mtd_device()

Signed-off-by: Matthias Kaehlcke <matthias@kaehlcke.net>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

[MTD] use list_for_each_entry() in add_mtd_device()

Signed-off-by: Matthias Kaehlcke <matthias@kaehlcke.net>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

[MTD] Unlocking all Intel flash that is locked on power up.

Patch for unlocking all Intel flash that has instant locking on power up.
The patch has been tested on Intel M18, P30 and J3D Strata Flash.
1. The automatic unlocking can be disabled for a particular partition
in the map or the command line.
a. For the bit mask in the map it should look like:
.mask_flags = MTD_POWERUP_LOCK,
b. For the command line parsing it should look like:
mtdparts=0x80000(bootloader)lk
2. This will only unlock parts with instant individual block locking.
Intel parts with legacy unlocking will not be unlocked.

Signed-off-by: Justin Treon <justin_treon@yahoo.com>
Signed-off-by: Jared Hulbert <jaredeh@gmail.com>
Acked-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

[MTD] mtdcore.c: share syms with mtd_blkdev.c

Fix the sparse warnings generated by the implicit
dependency of mtd_blkdevs.c and mtd_core.c for the
two symbols mtd_table and mtd_table_mutex. This is
done by adding an local header file mtdcore.h to
define these (including the warning about the
non-proliferation of these symbols).

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

[PATCH] remove many unneeded #includes of sched.h

After Al Viro (finally) succeeded in removing the sched.h #include in module.h
recently, it makes sense again to remove other superfluous sched.h includes.
There are quite a lot of files which include it but don't actually need
anything defined in there. Presumably these includes were once needed for
macros that used to live in sched.h, but moved to other header files in the
course of cleaning it up.

To ease the pain, this time I did not fiddle with any header files and only
removed #includes from .c-files, which tend to cause less trouble.

Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha,
arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig,
allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all
configs in arch/arm/configs on arm. I also checked that no new warnings were
introduced by the patch (actually, some warnings are removed that were emitted
by unnecessarily included header files).

Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[MTD] Use EXPORT_SYMBOL_GPL() for exported symbols.

While we're fixing up the newly-added symbol, change the neighbouring ones
too, for consistency and also to reflect the author's interpretation of
the GPL -- which is that _no_ non-GPL modules are permitted. The author
always intended his code to be released under the GPL, and believes that
any new interpretation of 'EXPORT_SYMBOL' as being any different from
'EXPORT_SYMBOL_GPL' is entirely invalid; the GPL requires that _all_
exports have the semantics of the new 'EXPORT_SYMBOL_GPL', which means the
extra four characters are entirely redundant.

But since those four extra characters trigger the check for illegal
modules in a way that just EXPORT_SYMBOL does not, it's useful to change
anyway. This action in no way indicates an admission that there is any
legal distinction between the two states, and in particular does not
indicate that the author believes that non-GPL modules may use symbols
exported with EXPORT_SYMBOL alone.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

[MTD] return error code from get_mtd_device()

get_mtd_device() returns NULL in case of any failure. Teach it to return an
error code instead. Fix all users as well.

Signed-off-by: Artem Bityutskiy <dedekind@infradead.org>

[MTD] add get and put methods

This patch adds get_device() and put_device() methods to the MTD description
structure (struct mtd_info). These methods are called by MTD whenever the MTD
device is get or put. They are needed when the underlying driver is something
smarter then just flash chip driver, for example UBI.

Signed-off-by: Artem Bityutskiy <dedekind@infradead.org>

[MTD] add get_mtd_device_nm() function

This patch adds one more function to the MTD interface to make it possible to
open MTD devices by their names, not only numbers. This is very handy in many
situations. Also, MTD device number depend on load order and may vary, while
names are fixed.

Signed-off-by: Artem Bityutskiy <dedekind@infradead.org>

[MTD] Unlock NOR flash automatically where necessary

Introduce the MTD_STUPID_LOCK flag which indicates that the flash chip is
always locked after power-up, so all sectors need to be unlocked before it
is usable.

If this flag is set, and the chip provides an unlock() operation,
mtd_add_device will unlock the whole MTD device if it's writeable. This
means that non-writeable partitions will stay locked.

Set MTD_STUPID_LOCK in fixup_use_atmel_lock() so that these chips will work
as expected.

Signed-off-by: Håvard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

Remove obsolete #include <linux/config.h>

Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

[MTD] assume mtd->writesize is 1 for NOR flashes

Signed-off-by: Artem B. Bityitskiy

[MTD] Remove the only useless readv implementation

Removing readv from struct mtd_info broke block2mtd. Remove the
reference and the useless default implementation.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

[PATCH] Kill ifdefs in mtdcore.c

Kill unneccessary ifdefs in mtdcore.c.

Signed-off-by: Pavel Machek <pavel@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] sem2mutex: drivers/mtd/

Semaphore to mutex conversion.

The conversion was generated via scripts, and the result was validated
automatically via a script as well.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[MTD] core: Clean up trailing white spaces

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

[MTD] Remove deprecated power management functions

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

[MTD] Fix unregister_mtd_user() public function documentation.

Signed-off-by: Artem B. Bityuckiy <dedekind@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!